From 14faa838fe92f650976583500f1336d7f5b19aea Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 16 Sep 2026 18:26:41 +0000
Subject: [PATCH 01/12] Add C# Dev Kit v11 compatibility check

Co-authored-by: dibarbet <5749229+dibarbet@users.noreply.github.com>
---
 src/checkCSharpDevKitVersion.ts               | 27 ++++++++++
 src/main.ts                                   |  2 +
 .../checkCSharpDevKitVersion.test.ts          | 49 +++++++++++++++++++
 3 files changed, 78 insertions(+)
 create mode 100644 src/checkCSharpDevKitVersion.ts
 create mode 100644 test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts

diff --git a/src/checkCSharpDevKitVersion.ts b/src/checkCSharpDevKitVersion.ts
new file mode 100644
index 000000000..b24217c0c
--- /dev/null
+++ b/src/checkCSharpDevKitVersion.ts
@@ -0,0 +1,27 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as vscode from 'vscode';
+import { major } from 'semver';
+import { CSharpDevKitExports } from './csharpDevKitExports';
+
+const requiredCSharpDevKitMajorVersion = 11;
+
+export async function checkCSharpDevKitVersion(
+    csharpDevKitExtension: vscode.Extension<CSharpDevKitExports> | undefined
+): Promise<void> {
+    if (
+        !csharpDevKitExtension ||
+        major(csharpDevKitExtension.packageJSON.version) >= requiredCSharpDevKitMajorVersion
+    ) {
+        return;
+    }
+
+    const message = vscode.l10n.t(
+        'This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
+    );
+    await vscode.window.showErrorMessage(message);
+    throw new Error(message);
+}
diff --git a/src/main.ts b/src/main.ts
index 600619a2f..5235d33de 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -27,6 +27,7 @@ import { checkDotNetRuntimeExtensionVersion } from './checkDotNetRuntimeExtensio
 import { checkIsSupportedPlatform } from './checkSupportedPlatform';
 import { activateRoslyn } from './activateRoslyn';
 import { LimitedActivationStatus } from './shared/limitedActivationStatus';
+import { checkCSharpDevKitVersion } from './checkCSharpDevKitVersion';
 
 export async function activate(
     context: vscode.ExtensionContext
@@ -71,6 +72,7 @@ export async function activate(
     const requiredPackageIds: string[] = ['Debugger', 'Razor'];
 
     const csharpDevkitExtension = getCSharpDevKit();
+    await checkCSharpDevKitVersion(csharpDevkitExtension);
     const useOmnisharpServer = !csharpDevkitExtension && commonOptions.useOmnisharpServer;
     if (useOmnisharpServer) {
         requiredPackageIds.push('OmniSharp');
diff --git a/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts b/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
new file mode 100644
index 000000000..cdadbb9e3
--- /dev/null
+++ b/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
@@ -0,0 +1,49 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as vscode from 'vscode';
+import { beforeEach, describe, expect, jest, test } from '@jest/globals';
+import { checkCSharpDevKitVersion } from '../../../src/checkCSharpDevKitVersion';
+import { CSharpDevKitExports } from '../../../src/csharpDevKitExports';
+
+describe('C# Dev Kit version check', () => {
+    beforeEach(() => {
+        jest.restoreAllMocks();
+    });
+
+    test('allows activation when C# Dev Kit is not installed', async () => {
+        const showErrorMessage = jest.spyOn(vscode.window, 'showErrorMessage');
+
+        await checkCSharpDevKitVersion(undefined);
+
+        expect(showErrorMessage).not.toHaveBeenCalled();
+    });
+
+    test.each(['11.0.0', '11.0.0-pre.1', '12.0.0'])(
+        'allows activation with C# Dev Kit version %s',
+        async (version) => {
+            const showErrorMessage = jest.spyOn(vscode.window, 'showErrorMessage');
+
+            await checkCSharpDevKitVersion(createExtension(version));
+
+            expect(showErrorMessage).not.toHaveBeenCalled();
+        }
+    );
+
+    test('blocks activation with an older C# Dev Kit version', async () => {
+        const showErrorMessage = jest.spyOn(vscode.window, 'showErrorMessage').mockResolvedValue(undefined);
+
+        await expect(checkCSharpDevKitVersion(createExtension('10.9.99'))).rejects.toThrow(
+            'This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
+        );
+        expect(showErrorMessage).toHaveBeenCalledTimes(1);
+    });
+});
+
+function createExtension(version: string): vscode.Extension<CSharpDevKitExports> {
+    return {
+        packageJSON: { version },
+    } as vscode.Extension<CSharpDevKitExports>;
+}

From db7ef15801cec35683e30297857e65e0a5743d69 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 16 Sep 2026 18:27:30 +0000
Subject: [PATCH 02/12] Format C# Dev Kit compatibility tests

Co-authored-by: dibarbet <5749229+dibarbet@users.noreply.github.com>
---
 .../unitTests/checkCSharpDevKitVersion.test.ts      | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts b/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
index cdadbb9e3..e564aa4c4 100644
--- a/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
+++ b/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
@@ -21,16 +21,13 @@ describe('C# Dev Kit version check', () => {
         expect(showErrorMessage).not.toHaveBeenCalled();
     });
 
-    test.each(['11.0.0', '11.0.0-pre.1', '12.0.0'])(
-        'allows activation with C# Dev Kit version %s',
-        async (version) => {
-            const showErrorMessage = jest.spyOn(vscode.window, 'showErrorMessage');
+    test.each(['11.0.0', '11.0.0-pre.1', '12.0.0'])('allows activation with C# Dev Kit version %s', async (version) => {
+        const showErrorMessage = jest.spyOn(vscode.window, 'showErrorMessage');
 
-            await checkCSharpDevKitVersion(createExtension(version));
+        await checkCSharpDevKitVersion(createExtension(version));
 
-            expect(showErrorMessage).not.toHaveBeenCalled();
-        }
-    );
+        expect(showErrorMessage).not.toHaveBeenCalled();
+    });
 
     test('blocks activation with an older C# Dev Kit version', async () => {
         const showErrorMessage = jest.spyOn(vscode.window, 'showErrorMessage').mockResolvedValue(undefined);

From 90a1273ea9e27778fc0da82ddb85fa1a1c716e0c Mon Sep 17 00:00:00 2001
From: David Barbet <dabarbet@microsoft.com>
Date: Wed, 16 Sep 2026 11:39:13 -0700
Subject: [PATCH 03/12] Add localization entry for C# Dev Kit version
 requirement

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: b3a2d96f-a3d1-4cad-868f-50dc15c71516
---
 l10n/bundle.l10n.json | 1 +
 1 file changed, 1 insertion(+)

diff --git a/l10n/bundle.l10n.json b/l10n/bundle.l10n.json
index 27e7d2c6a..3479f4011 100644
--- a/l10n/bundle.l10n.json
+++ b/l10n/bundle.l10n.json
@@ -5,6 +5,7 @@
   "Update and reload": "Update and reload",
   "The {0} extension requires at least {1} of the .NET Install Tool ({2}) extension. Please update to continue": "The {0} extension requires at least {1} of the .NET Install Tool ({2}) extension. Please update to continue",
   "Version {0} of the .NET Install Tool ({1}) was not found, {2} will not activate.": "Version {0} of the .NET Install Tool ({1}) was not found, {2} will not activate.",
+  "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.": "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.",
   ".NET Test Log": ".NET Test Log",
   ".NET NuGet Restore": ".NET NuGet Restore",
   "Cannot create .NET debug configurations. No workspace folder was selected.": "Cannot create .NET debug configurations. No workspace folder was selected.",

From 2b55f2345d170968027f9ac5c4587a6b89222c2f Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 16 Sep 2026 20:39:39 +0000
Subject: [PATCH 04/12] Require C# Dev Kit version 11.1

Co-authored-by: dibarbet <5749229+dibarbet@users.noreply.github.com>
---
 l10n/bundle.l10n.json                                 |  2 +-
 src/checkCSharpDevKitVersion.ts                       | 11 ++++-------
 .../unitTests/checkCSharpDevKitVersion.test.ts        |  6 +++---
 3 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/l10n/bundle.l10n.json b/l10n/bundle.l10n.json
index 3479f4011..3488332c4 100644
--- a/l10n/bundle.l10n.json
+++ b/l10n/bundle.l10n.json
@@ -5,7 +5,7 @@
   "Update and reload": "Update and reload",
   "The {0} extension requires at least {1} of the .NET Install Tool ({2}) extension. Please update to continue": "The {0} extension requires at least {1} of the .NET Install Tool ({2}) extension. Please update to continue",
   "Version {0} of the .NET Install Tool ({1}) was not found, {2} will not activate.": "Version {0} of the .NET Install Tool ({1}) was not found, {2} will not activate.",
-  "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.": "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.",
+  "This version of the C# extension requires C# Dev Kit version 11.1 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.": "This version of the C# extension requires C# Dev Kit version 11.1 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.",
   ".NET Test Log": ".NET Test Log",
   ".NET NuGet Restore": ".NET NuGet Restore",
   "Cannot create .NET debug configurations. No workspace folder was selected.": "Cannot create .NET debug configurations. No workspace folder was selected.",
diff --git a/src/checkCSharpDevKitVersion.ts b/src/checkCSharpDevKitVersion.ts
index b24217c0c..861c74cd2 100644
--- a/src/checkCSharpDevKitVersion.ts
+++ b/src/checkCSharpDevKitVersion.ts
@@ -4,23 +4,20 @@
  *--------------------------------------------------------------------------------------------*/
 
 import * as vscode from 'vscode';
-import { major } from 'semver';
+import { lt } from 'semver';
 import { CSharpDevKitExports } from './csharpDevKitExports';
 
-const requiredCSharpDevKitMajorVersion = 11;
+const requiredCSharpDevKitVersion = '11.1.0';
 
 export async function checkCSharpDevKitVersion(
     csharpDevKitExtension: vscode.Extension<CSharpDevKitExports> | undefined
 ): Promise<void> {
-    if (
-        !csharpDevKitExtension ||
-        major(csharpDevKitExtension.packageJSON.version) >= requiredCSharpDevKitMajorVersion
-    ) {
+    if (!csharpDevKitExtension || !lt(csharpDevKitExtension.packageJSON.version, requiredCSharpDevKitVersion)) {
         return;
     }
 
     const message = vscode.l10n.t(
-        'This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
+        'This version of the C# extension requires C# Dev Kit version 11.1 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
     );
     await vscode.window.showErrorMessage(message);
     throw new Error(message);
diff --git a/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts b/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
index e564aa4c4..d4bbbeae3 100644
--- a/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
+++ b/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
@@ -21,7 +21,7 @@ describe('C# Dev Kit version check', () => {
         expect(showErrorMessage).not.toHaveBeenCalled();
     });
 
-    test.each(['11.0.0', '11.0.0-pre.1', '12.0.0'])('allows activation with C# Dev Kit version %s', async (version) => {
+    test.each(['11.1.0', '11.1.1-pre.1', '12.0.0'])('allows activation with C# Dev Kit version %s', async (version) => {
         const showErrorMessage = jest.spyOn(vscode.window, 'showErrorMessage');
 
         await checkCSharpDevKitVersion(createExtension(version));
@@ -32,8 +32,8 @@ describe('C# Dev Kit version check', () => {
     test('blocks activation with an older C# Dev Kit version', async () => {
         const showErrorMessage = jest.spyOn(vscode.window, 'showErrorMessage').mockResolvedValue(undefined);
 
-        await expect(checkCSharpDevKitVersion(createExtension('10.9.99'))).rejects.toThrow(
-            'This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
+        await expect(checkCSharpDevKitVersion(createExtension('11.0.99'))).rejects.toThrow(
+            'This version of the C# extension requires C# Dev Kit version 11.1 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
         );
         expect(showErrorMessage).toHaveBeenCalledTimes(1);
     });

From 8e96cdc7ae5242b7b95a03a7c48f7be6e926bacc Mon Sep 17 00:00:00 2001
From: David Barbet <dabarbet@microsoft.com>
Date: Wed, 16 Sep 2026 13:45:31 -0700
Subject: [PATCH 05/12] Bump C# extension to 11.1 and restore Dev Kit v11
 requirement

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: b3a2d96f-a3d1-4cad-868f-50dc15c71516
---
 l10n/bundle.l10n.json                                 |  2 +-
 src/checkCSharpDevKitVersion.ts                       | 11 +++++++----
 .../unitTests/checkCSharpDevKitVersion.test.ts        |  6 +++---
 version.json                                          |  2 +-
 4 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/l10n/bundle.l10n.json b/l10n/bundle.l10n.json
index 3488332c4..3479f4011 100644
--- a/l10n/bundle.l10n.json
+++ b/l10n/bundle.l10n.json
@@ -5,7 +5,7 @@
   "Update and reload": "Update and reload",
   "The {0} extension requires at least {1} of the .NET Install Tool ({2}) extension. Please update to continue": "The {0} extension requires at least {1} of the .NET Install Tool ({2}) extension. Please update to continue",
   "Version {0} of the .NET Install Tool ({1}) was not found, {2} will not activate.": "Version {0} of the .NET Install Tool ({1}) was not found, {2} will not activate.",
-  "This version of the C# extension requires C# Dev Kit version 11.1 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.": "This version of the C# extension requires C# Dev Kit version 11.1 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.",
+  "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.": "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.",
   ".NET Test Log": ".NET Test Log",
   ".NET NuGet Restore": ".NET NuGet Restore",
   "Cannot create .NET debug configurations. No workspace folder was selected.": "Cannot create .NET debug configurations. No workspace folder was selected.",
diff --git a/src/checkCSharpDevKitVersion.ts b/src/checkCSharpDevKitVersion.ts
index 861c74cd2..b24217c0c 100644
--- a/src/checkCSharpDevKitVersion.ts
+++ b/src/checkCSharpDevKitVersion.ts
@@ -4,20 +4,23 @@
  *--------------------------------------------------------------------------------------------*/
 
 import * as vscode from 'vscode';
-import { lt } from 'semver';
+import { major } from 'semver';
 import { CSharpDevKitExports } from './csharpDevKitExports';
 
-const requiredCSharpDevKitVersion = '11.1.0';
+const requiredCSharpDevKitMajorVersion = 11;
 
 export async function checkCSharpDevKitVersion(
     csharpDevKitExtension: vscode.Extension<CSharpDevKitExports> | undefined
 ): Promise<void> {
-    if (!csharpDevKitExtension || !lt(csharpDevKitExtension.packageJSON.version, requiredCSharpDevKitVersion)) {
+    if (
+        !csharpDevKitExtension ||
+        major(csharpDevKitExtension.packageJSON.version) >= requiredCSharpDevKitMajorVersion
+    ) {
         return;
     }
 
     const message = vscode.l10n.t(
-        'This version of the C# extension requires C# Dev Kit version 11.1 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
+        'This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
     );
     await vscode.window.showErrorMessage(message);
     throw new Error(message);
diff --git a/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts b/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
index d4bbbeae3..e564aa4c4 100644
--- a/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
+++ b/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
@@ -21,7 +21,7 @@ describe('C# Dev Kit version check', () => {
         expect(showErrorMessage).not.toHaveBeenCalled();
     });
 
-    test.each(['11.1.0', '11.1.1-pre.1', '12.0.0'])('allows activation with C# Dev Kit version %s', async (version) => {
+    test.each(['11.0.0', '11.0.0-pre.1', '12.0.0'])('allows activation with C# Dev Kit version %s', async (version) => {
         const showErrorMessage = jest.spyOn(vscode.window, 'showErrorMessage');
 
         await checkCSharpDevKitVersion(createExtension(version));
@@ -32,8 +32,8 @@ describe('C# Dev Kit version check', () => {
     test('blocks activation with an older C# Dev Kit version', async () => {
         const showErrorMessage = jest.spyOn(vscode.window, 'showErrorMessage').mockResolvedValue(undefined);
 
-        await expect(checkCSharpDevKitVersion(createExtension('11.0.99'))).rejects.toThrow(
-            'This version of the C# extension requires C# Dev Kit version 11.1 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
+        await expect(checkCSharpDevKitVersion(createExtension('10.9.99'))).rejects.toThrow(
+            'This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
         );
         expect(showErrorMessage).toHaveBeenCalledTimes(1);
     });
diff --git a/version.json b/version.json
index 72ac11e7f..fa720aa48 100644
--- a/version.json
+++ b/version.json
@@ -1,6 +1,6 @@
 {
     "$schema": "https://raw.githubusercontent.com/dotnet/Nerdbank.GitVersioning/master/src/NerdBank.GitVersioning/version.schema.json",
-    "version": "2.152",
+    "version": "11.1",
     "publicReleaseRefSpec": [
         "^refs/heads/release$",
         "^refs/heads/prerelease$",

From 342a1209c278ff325f98657edf8a5f420ccbd78e Mon Sep 17 00:00:00 2001
From: David Barbet <dabarbet@microsoft.com>
Date: Wed, 16 Sep 2026 14:06:38 -0700
Subject: [PATCH 06/12] fixup

---
 l10n/bundle.l10n.json                                        | 2 +-
 src/checkCSharpDevKitVersion.ts                              | 4 ++--
 test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts | 1 +
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/l10n/bundle.l10n.json b/l10n/bundle.l10n.json
index 3479f4011..2b9777255 100644
--- a/l10n/bundle.l10n.json
+++ b/l10n/bundle.l10n.json
@@ -5,7 +5,7 @@
   "Update and reload": "Update and reload",
   "The {0} extension requires at least {1} of the .NET Install Tool ({2}) extension. Please update to continue": "The {0} extension requires at least {1} of the .NET Install Tool ({2}) extension. Please update to continue",
   "Version {0} of the .NET Install Tool ({1}) was not found, {2} will not activate.": "Version {0} of the .NET Install Tool ({1}) was not found, {2} will not activate.",
-  "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.": "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.",
+  "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the latest pre-release version of C# Dev Kit or use the release version of the C# extension.": "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the latest pre-release version of C# Dev Kit or use the release version of the C# extension.",
   ".NET Test Log": ".NET Test Log",
   ".NET NuGet Restore": ".NET NuGet Restore",
   "Cannot create .NET debug configurations. No workspace folder was selected.": "Cannot create .NET debug configurations. No workspace folder was selected.",
diff --git a/src/checkCSharpDevKitVersion.ts b/src/checkCSharpDevKitVersion.ts
index b24217c0c..b4fc09289 100644
--- a/src/checkCSharpDevKitVersion.ts
+++ b/src/checkCSharpDevKitVersion.ts
@@ -20,8 +20,8 @@ export async function checkCSharpDevKitVersion(
     }
 
     const message = vscode.l10n.t(
-        'This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
+        'This version of the C# extension requires C# Dev Kit version 11 or later. Please install the latest pre-release version of C# Dev Kit or use the release version of the C# extension.'
     );
-    await vscode.window.showErrorMessage(message);
+    await vscode.window.showErrorMessage(message, { modal: true });
     throw new Error(message);
 }
diff --git a/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts b/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
index e564aa4c4..3dceaf9d8 100644
--- a/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
+++ b/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
@@ -36,6 +36,7 @@ describe('C# Dev Kit version check', () => {
             'This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
         );
         expect(showErrorMessage).toHaveBeenCalledTimes(1);
+        expect(showErrorMessage).toHaveBeenCalledWith(expect.any(String), { modal: true });
     });
 });
 

From 968f2afd56650d8d7606262ed611623c70c94e66 Mon Sep 17 00:00:00 2001
From: David Barbet <dabarbet@microsoft.com>
Date: Wed, 16 Sep 2026 14:47:51 -0700
Subject: [PATCH 07/12] feedback

---
 CHANGELOG.md                                        |  4 ++++
 azure-pipelines.yml                                 |  2 ++
 azure-pipelines/test-matrix.yml                     | 10 +++++++---
 l10n/bundle.l10n.json                               |  1 +
 src/checkCSharpDevKitVersion.ts                     |  9 +++++++--
 .../unitTests/checkCSharpDevKitVersion.test.ts      | 13 +++++++++++--
 test/vscodeLauncher.ts                              |  2 +-
 7 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 67402833b..183e66080 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,10 @@
 - Diagnostics related feature requests and improvements [#5951](https://github.com/dotnet/vscode-csharp/issues/5951)
 - Debug from .csproj and .sln [#5876](https://github.com/dotnet/vscode-csharp/issues/5876)
 
+# 11.1.x
+
+* Require C# Dev Kit version 11 or later (PR: [#9776](https://github.com/dotnet/vscode-csharp/pull/9776))
+
 # 2.152.x
 
 * Update Roslyn to 5.12.0-1.26465.4 (PR: [#9772](https://github.com/dotnet/vscode-csharp/pull/9772))
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 352a7232b..282686b43 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -85,6 +85,7 @@ stages:
       os: linux
       # Prefer the dotnet from the container.
       installDotNet: false
+      runDevKitTests: false
       testVSCodeVersion: $(testVSCodeVersion)
       pool:
         name: NetCore-Public
@@ -102,6 +103,7 @@ stages:
       os: linux
       # Prefer the dotnet from the container.
       installDotNet: false
+      runDevKitTests: false
       testVSCodeVersion: $(testVSCodeVersion)
       pool:
         name: NetCore-Public
diff --git a/azure-pipelines/test-matrix.yml b/azure-pipelines/test-matrix.yml
index 658000533..a12982081 100644
--- a/azure-pipelines/test-matrix.yml
+++ b/azure-pipelines/test-matrix.yml
@@ -10,6 +10,9 @@ parameters:
     type: boolean
   - name: testVSCodeVersion
     type: string
+  - name: runDevKitTests
+    type: boolean
+    default: true
 
 jobs:
 - job:
@@ -21,9 +24,10 @@ jobs:
       CSharpIntegrationTests:
         npmCommand: test:integration:csharp
         isIntegration: true
-      DevKitTests:
-        npmCommand: test:integration:devkit
-        isIntegration: true
+      ${{ if parameters.runDevKitTests }}:
+        DevKitTests:
+          npmCommand: test:integration:devkit
+          isIntegration: true
       RazorCohostTests:
         npmCommand: test:integration:razor:cohost
         isIntegration: true
diff --git a/l10n/bundle.l10n.json b/l10n/bundle.l10n.json
index 2b9777255..0e2184b34 100644
--- a/l10n/bundle.l10n.json
+++ b/l10n/bundle.l10n.json
@@ -6,6 +6,7 @@
   "The {0} extension requires at least {1} of the .NET Install Tool ({2}) extension. Please update to continue": "The {0} extension requires at least {1} of the .NET Install Tool ({2}) extension. Please update to continue",
   "Version {0} of the .NET Install Tool ({1}) was not found, {2} will not activate.": "Version {0} of the .NET Install Tool ({1}) was not found, {2} will not activate.",
   "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the latest pre-release version of C# Dev Kit or use the release version of the C# extension.": "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the latest pre-release version of C# Dev Kit or use the release version of the C# extension.",
+  "Open C# Dev Kit": "Open C# Dev Kit",
   ".NET Test Log": ".NET Test Log",
   ".NET NuGet Restore": ".NET NuGet Restore",
   "Cannot create .NET debug configurations. No workspace folder was selected.": "Cannot create .NET debug configurations. No workspace folder was selected.",
diff --git a/src/checkCSharpDevKitVersion.ts b/src/checkCSharpDevKitVersion.ts
index b4fc09289..1dde7b404 100644
--- a/src/checkCSharpDevKitVersion.ts
+++ b/src/checkCSharpDevKitVersion.ts
@@ -6,6 +6,7 @@
 import * as vscode from 'vscode';
 import { major } from 'semver';
 import { CSharpDevKitExports } from './csharpDevKitExports';
+import { csharpDevkitExtensionId } from './utils/getCSharpDevKit';
 
 const requiredCSharpDevKitMajorVersion = 11;
 
@@ -20,8 +21,12 @@ export async function checkCSharpDevKitVersion(
     }
 
     const message = vscode.l10n.t(
-        'This version of the C# extension requires C# Dev Kit version 11 or later. Please install the latest pre-release version of C# Dev Kit or use the release version of the C# extension.'
+        'C# Dev Kit version 11 or later is required. Please switch to the pre-release version of the C# Dev Kit.'
     );
-    await vscode.window.showErrorMessage(message, { modal: true });
+    const openCSharpDevKit = vscode.l10n.t('Open C# Dev Kit');
+    const selection = await vscode.window.showErrorMessage(message, { modal: true }, openCSharpDevKit);
+    if (selection === openCSharpDevKit) {
+        await vscode.commands.executeCommand('extension.open', csharpDevkitExtensionId);
+    }
     throw new Error(message);
 }
diff --git a/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts b/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
index 3dceaf9d8..0197c87fd 100644
--- a/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
+++ b/test/lsptoolshost/unitTests/checkCSharpDevKitVersion.test.ts
@@ -33,10 +33,19 @@ describe('C# Dev Kit version check', () => {
         const showErrorMessage = jest.spyOn(vscode.window, 'showErrorMessage').mockResolvedValue(undefined);
 
         await expect(checkCSharpDevKitVersion(createExtension('10.9.99'))).rejects.toThrow(
-            'This version of the C# extension requires C# Dev Kit version 11 or later. Please install the pre-release version of C# Dev Kit or use the release version of the C# extension.'
+            'C# Dev Kit version 11 or later is required. Please switch to the pre-release version of the C# Dev Kit.'
         );
         expect(showErrorMessage).toHaveBeenCalledTimes(1);
-        expect(showErrorMessage).toHaveBeenCalledWith(expect.any(String), { modal: true });
+        expect(showErrorMessage).toHaveBeenCalledWith(expect.any(String), { modal: true }, 'Open C# Dev Kit');
+    });
+
+    test('opens C# Dev Kit when requested', async () => {
+        jest.spyOn(vscode.window, 'showErrorMessage').mockResolvedValue('Open C# Dev Kit' as never);
+        const executeCommand = jest.spyOn(vscode.commands, 'executeCommand').mockResolvedValue(undefined);
+
+        await expect(checkCSharpDevKitVersion(createExtension('10.9.99'))).rejects.toThrow();
+
+        expect(executeCommand).toHaveBeenCalledWith('extension.open', 'ms-dotnettools.csdevkit');
     });
 });
 
diff --git a/test/vscodeLauncher.ts b/test/vscodeLauncher.ts
index 639925b8d..7895e173d 100644
--- a/test/vscodeLauncher.ts
+++ b/test/vscodeLauncher.ts
@@ -32,7 +32,7 @@ export async function prepareVSCodeAndExecuteTests(
     const extensionsToInstall = [
         'ms-dotnettools.vscode-dotnet-runtime@3.0.0',
         'ms-dotnettools.csharp',
-        'ms-dotnettools.csdevkit@1.92.5',
+        'ms-dotnettools.csdevkit@11.0.2',
     ];
 
     await installExtensions(extensionsToInstall, cli, args);

From 794042bf5f3fe8abc2962a416fb472a955e7a185 Mon Sep 17 00:00:00 2001
From: David Barbet <dabarbet@microsoft.com>
Date: Wed, 16 Sep 2026 15:21:38 -0700
Subject: [PATCH 08/12] fixes

---
 CHANGELOG.md          | 4 ----
 l10n/bundle.l10n.json | 2 +-
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 183e66080..9a45dd4bd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,11 +4,7 @@
 - Debug from .csproj and .sln [#5876](https://github.com/dotnet/vscode-csharp/issues/5876)
 
 # 11.1.x
-
 * Require C# Dev Kit version 11 or later (PR: [#9776](https://github.com/dotnet/vscode-csharp/pull/9776))
-
-# 2.152.x
-
 * Update Roslyn to 5.12.0-1.26465.4 (PR: [#9772](https://github.com/dotnet/vscode-csharp/pull/9772))
   * Avoid cache misses due to cancellation in deprioritized analyzer cache (PR: [#85222](https://github.com/dotnet/roslyn/pull/85222))
   * Move the LanguageServerProjectLoader over to our priority queue (PR: [#85272](https://github.com/dotnet/roslyn/pull/85272))
diff --git a/l10n/bundle.l10n.json b/l10n/bundle.l10n.json
index 0e2184b34..a9d5f5ab2 100644
--- a/l10n/bundle.l10n.json
+++ b/l10n/bundle.l10n.json
@@ -5,7 +5,7 @@
   "Update and reload": "Update and reload",
   "The {0} extension requires at least {1} of the .NET Install Tool ({2}) extension. Please update to continue": "The {0} extension requires at least {1} of the .NET Install Tool ({2}) extension. Please update to continue",
   "Version {0} of the .NET Install Tool ({1}) was not found, {2} will not activate.": "Version {0} of the .NET Install Tool ({1}) was not found, {2} will not activate.",
-  "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the latest pre-release version of C# Dev Kit or use the release version of the C# extension.": "This version of the C# extension requires C# Dev Kit version 11 or later. Please install the latest pre-release version of C# Dev Kit or use the release version of the C# extension.",
+  "C# Dev Kit version 11 or later is required. Please switch to the pre-release version of the C# Dev Kit.": "C# Dev Kit version 11 or later is required. Please switch to the pre-release version of the C# Dev Kit.",
   "Open C# Dev Kit": "Open C# Dev Kit",
   ".NET Test Log": ".NET Test Log",
   ".NET NuGet Restore": ".NET NuGet Restore",

From fc7c3dfd1a5c2af089ae6bc2dd39e508d8ed822c Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 18 Sep 2026 01:04:13 +0000
Subject: [PATCH 09/12] Skip Source Link integration tests

Co-authored-by: dibarbet <5749229+dibarbet@users.noreply.github.com>
---
 .../integrationTests/gotoDefinition.integration.test.ts      | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/test/lsptoolshost/integrationTests/gotoDefinition.integration.test.ts b/test/lsptoolshost/integrationTests/gotoDefinition.integration.test.ts
index 6de730414..eb607964b 100644
--- a/test/lsptoolshost/integrationTests/gotoDefinition.integration.test.ts
+++ b/test/lsptoolshost/integrationTests/gotoDefinition.integration.test.ts
@@ -13,7 +13,6 @@ import {
     navigate,
     openFileInWorkspaceAsync,
     testIfCSharp,
-    testIfDevKit,
 } from './integrationHelpers';
 import { describe, beforeAll, beforeEach, afterAll, test, expect, afterEach } from '@jest/globals';
 
@@ -219,7 +218,7 @@ describe(`Go To Definition Tests`, () => {
         );
     });
 
-    testIfDevKit('Navigates to definition in source link', async () => {
+    test.skip('Navigates to definition in source link', async () => {
         await openFileInWorkspaceAsync(path.join('test', 'UnitTest1.cs'));
 
         // Get definitions
@@ -245,7 +244,7 @@ describe(`Go To Definition Tests`, () => {
         expect(vscode.window.activeTextEditor?.document.uri.path.toLowerCase()).toContain('symbolcache');
     });
 
-    testIfDevKit('Navigates from definition in source link source goes to source link', async () => {
+    test.skip('Navigates from definition in source link source goes to source link', async () => {
         await openFileInWorkspaceAsync(path.join('test', 'UnitTest1.cs'));
 
         // Get definitions

From 7a43df6ca7a9e9054f09bcd3ef4f2c7f51b40876 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 18 Sep 2026 01:04:49 +0000
Subject: [PATCH 10/12] Document Source Link test skip

Co-authored-by: dibarbet <5749229+dibarbet@users.noreply.github.com>
---
 .../integrationTests/gotoDefinition.integration.test.ts          | 1 +
 1 file changed, 1 insertion(+)

diff --git a/test/lsptoolshost/integrationTests/gotoDefinition.integration.test.ts b/test/lsptoolshost/integrationTests/gotoDefinition.integration.test.ts
index eb607964b..3bdf8d241 100644
--- a/test/lsptoolshost/integrationTests/gotoDefinition.integration.test.ts
+++ b/test/lsptoolshost/integrationTests/gotoDefinition.integration.test.ts
@@ -218,6 +218,7 @@ describe(`Go To Definition Tests`, () => {
         );
     });
 
+    // Re-enable when the C# Dev Kit v11 Source Link bug is fixed.
     test.skip('Navigates to definition in source link', async () => {
         await openFileInWorkspaceAsync(path.join('test', 'UnitTest1.cs'));
 

From 63e9a9878702b7d2582e24da8ccf1a83adc37119 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 18 Sep 2026 01:05:24 +0000
Subject: [PATCH 11/12] Document second Source Link test skip

Co-authored-by: dibarbet <5749229+dibarbet@users.noreply.github.com>
---
 .../integrationTests/gotoDefinition.integration.test.ts          | 1 +
 1 file changed, 1 insertion(+)

diff --git a/test/lsptoolshost/integrationTests/gotoDefinition.integration.test.ts b/test/lsptoolshost/integrationTests/gotoDefinition.integration.test.ts
index 3bdf8d241..894d8b168 100644
--- a/test/lsptoolshost/integrationTests/gotoDefinition.integration.test.ts
+++ b/test/lsptoolshost/integrationTests/gotoDefinition.integration.test.ts
@@ -245,6 +245,7 @@ describe(`Go To Definition Tests`, () => {
         expect(vscode.window.activeTextEditor?.document.uri.path.toLowerCase()).toContain('symbolcache');
     });
 
+    // Re-enable when the C# Dev Kit v11 Source Link bug is fixed.
     test.skip('Navigates from definition in source link source goes to source link', async () => {
         await openFileInWorkspaceAsync(path.join('test', 'UnitTest1.cs'));
 

From d838038cb9168252519d4dfd34e1a19ef1239ee2 Mon Sep 17 00:00:00 2001
From: David Barbet <dabarbet@microsoft.com>
Date: Fri, 18 Sep 2026 16:30:57 -0700
Subject: [PATCH 12/12] disable C#dk integration tests due to bugs

---
 azure-pipelines/test-matrix.yml               |  3 +-
 tasks/tests/omnisharptestTasks.ts             |  2 +-
 ...orkspaceSymbolProvider.integration.test.ts |  2 +-
 test/tasks/vscodeLauncher.test.ts             | 59 +++++++++++++++++++
 test/vscodeLauncher.ts                        |  7 ++-
 5 files changed, 69 insertions(+), 4 deletions(-)
 create mode 100644 test/tasks/vscodeLauncher.test.ts

diff --git a/azure-pipelines/test-matrix.yml b/azure-pipelines/test-matrix.yml
index a12982081..f12dd7f57 100644
--- a/azure-pipelines/test-matrix.yml
+++ b/azure-pipelines/test-matrix.yml
@@ -12,7 +12,8 @@ parameters:
     type: string
   - name: runDevKitTests
     type: boolean
-    default: true
+    # Re-enable once the C# Dev Kit v11 prerelease integration test failures are fixed.
+    default: false
 
 jobs:
 - job:
diff --git a/tasks/tests/omnisharptestTasks.ts b/tasks/tests/omnisharptestTasks.ts
index 218927824..e56414249 100644
--- a/tasks/tests/omnisharptestTasks.ts
+++ b/tasks/tests/omnisharptestTasks.ts
@@ -40,7 +40,7 @@ async function runOmnisharpJestIntegrationTest(
         CODE_WORKSPACE_ROOT: rootPath,
         OMNISHARP_ENGINE: engine,
         OMNISHARP_LOCATION: process.env.OMNISHARP_LOCATION,
-        CODE_DISABLE_EXTENSIONS: 'true',
+        CODE_DISABLE_CSHARP_DEV_KIT: 'true',
     };
 
     await runJestIntegrationTest(testAssetName, testFolder, workspaceFile, suiteName, env);
diff --git a/test/omnisharp/omnisharpIntegrationTests/workspaceSymbolProvider.integration.test.ts b/test/omnisharp/omnisharpIntegrationTests/workspaceSymbolProvider.integration.test.ts
index 7f6dff7cf..f256f8302 100644
--- a/test/omnisharp/omnisharpIntegrationTests/workspaceSymbolProvider.integration.test.ts
+++ b/test/omnisharp/omnisharpIntegrationTests/workspaceSymbolProvider.integration.test.ts
@@ -32,7 +32,7 @@ describeIfNotRazorOrGenerator(`WorkspaceSymbolProvider: ${testAssetWorkspace.des
         await omnisharpConfig.update('minFindSymbolsFilterLength', 2);
 
         const symbols = await GetWorkspaceSymbols('P');
-        expect(symbols.length).toEqual(0);
+        expect(symbols).toEqual([]);
     });
 
     test('Returns elements when minimum filter length is configured and search term is longer or equal', async function () {
diff --git a/test/tasks/vscodeLauncher.test.ts b/test/tasks/vscodeLauncher.test.ts
new file mode 100644
index 000000000..22f603a80
--- /dev/null
+++ b/test/tasks/vscodeLauncher.test.ts
@@ -0,0 +1,59 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as cp from 'child_process';
+import { downloadAndUnzipVSCode, resolveCliArgsFromVSCodeExecutablePath, runTests } from '@vscode/test-electron';
+import { beforeEach, describe, expect, jest, test } from '@jest/globals';
+import { prepareVSCodeAndExecuteTests } from '../vscodeLauncher';
+
+jest.mock('child_process');
+jest.mock('@vscode/test-electron');
+
+describe('VS Code test launcher', () => {
+    beforeEach(() => {
+        jest.clearAllMocks();
+        jest.mocked(downloadAndUnzipVSCode).mockResolvedValue('code');
+        jest.mocked(resolveCliArgsFromVSCodeExecutablePath).mockReturnValue(['code']);
+        jest.mocked(runTests).mockResolvedValue(0);
+        jest.mocked(cp.spawnSync).mockReturnValue({
+            pid: 1,
+            output: [],
+            stdout: '',
+            stderr: '',
+            status: 0,
+            signal: null,
+        });
+    });
+
+    test.each([
+        { flag: undefined, disabled: false },
+        { flag: 'false', disabled: false },
+        { flag: 'true', disabled: true },
+    ])('CODE_DISABLE_CSHARP_DEV_KIT=$flag disables Dev Kit: $disabled', async ({ flag, disabled }) => {
+        const env = { CODE_DISABLE_CSHARP_DEV_KIT: flag };
+
+        await expect(prepareVSCodeAndExecuteTests('extension', 'tests', 'workspace', 'user-data', env)).resolves.toBe(
+            0
+        );
+
+        expect(runTests).toHaveBeenCalledTimes(1);
+        const options = jest.mocked(runTests).mock.calls[0][0];
+        expect(options.extensionDevelopmentPath).toBe('extension');
+        expect(options.extensionTestsPath).toBe('tests');
+        expect(options.extensionTestsEnv).toBe(env);
+        expect(options.launchArgs).toEqual(
+            expect.arrayContaining([
+                'workspace',
+                '-n',
+                '--user-data-dir',
+                'user-data',
+                '--log',
+                'ms-dotnettools.csharp:trace',
+            ])
+        );
+        expect(options.launchArgs?.includes('--disable-extension=ms-dotnettools.csdevkit')).toBe(disabled);
+        expect(options.launchArgs).not.toContain('--disable-extensions');
+    });
+});
diff --git a/test/vscodeLauncher.ts b/test/vscodeLauncher.ts
index 7895e173d..937443bc3 100644
--- a/test/vscodeLauncher.ts
+++ b/test/vscodeLauncher.ts
@@ -28,7 +28,7 @@ export async function prepareVSCodeAndExecuteTests(
 
     // Different test runs may want to have Dev Kit be active or in-active.
     // Rather than having to uninstall Dev Kit between different test runs, we use workspace settings
-    // to control which extensions are active - and we always install Dev Kit.
+    // and launch arguments to control which extensions are active - and we always install Dev Kit.
     const extensionsToInstall = [
         'ms-dotnettools.vscode-dotnet-runtime@3.0.0',
         'ms-dotnettools.csharp',
@@ -56,6 +56,11 @@ export async function prepareVSCodeAndExecuteTests(
     }
 
     const launchArgs = [workspacePath, '-n', '--user-data-dir', userDataDir, '--log', 'ms-dotnettools.csharp:trace'];
+    if (env.CODE_DISABLE_CSHARP_DEV_KIT === 'true') {
+        // Disabling all extensions would also disable C#'s required .NET runtime extension.
+        launchArgs.push('--disable-extension=ms-dotnettools.csdevkit');
+    }
+
     if (process.platform === 'linux') {
         // CI containers have a small /dev/shm allocation, which can cause the renderer to crash.
         launchArgs.push('--disable-dev-shm-usage');