C# DevKit not fully functional

[luca-piccioni]

Issue Description

I'm unable to use C# DevKit extension on WSL2 remote connection.

VS Code About:
Version: 1.102.3 (user setup)
Commit: 488a1f239235055e34e673291fb8d8c810886f81
Date: 2025-07-29T03:00:23.339Z
Electron: 35.6.0
ElectronBuildId: 11847422
Chromium: 134.0.6998.205
Node.js: 22.15.1
V8: 13.4.114.21-electron.0
OS: Windows_NT x64 10.0.26100

dotnet SDKs on WSL2:

nvidia@Betelgeuse:~$ whereis dotnet
dotnet: /home/nvidia/.dotnet/dotnet /mnt/c/Program Files/dotnet/dotnet.exe

nvidia@Betelgeuse:~$ dotnet --list-sdks
6.0.428 [/home/nvidia/.dotnet/sdk]
8.0.416 [/home/nvidia/.dotnet/sdk]
9.0.308 [/home/nvidia/.dotnet/sdk]
10.0.100 [/home/nvidia/.dotnet/sdk]

nvidia@Betelgeuse:~$ tail -n 2 .profile 
export DOTNET_ROOT="$HOME/.dotnet"
export PATH="$HOME/.dotnet:$PATH"

Steps to Reproduce

• Open remote connection WSL2
• Install C# DevKit extension (Installs 1.80.7)
• Automatically install C# extension:

  Installing C# dependencies...
Platform: linux, x86_64, name=ubuntu, version=20.04

Downloading package 'OmniSharp for Linux (x64)' (38583 KB).................... Done!
Validating download...
Integrity Check succeeded.
Installing package 'OmniSharp for Linux (x64)'

Downloading package '.NET Core Debugger (linux / x64)' (59506 KB).................... Done!
Validating download...
Integrity Check succeeded.
Installing package '.NET Core Debugger (linux / x64)'

Downloading package 'Razor Language Server (Linux / x64)' (61682 KB).................... Done!
Installing package 'Razor Language Server (Linux / x64)'

Finished

I get the error:

2025-12-02 11:33:06.510 [info] The C# extension is installed, but has version 1.23.16 which is incompatible with C# Dev Kit.

(Infact it is installed automatically).

• Switch C# to pre-release version: automatically install version 2.0.251
• Reload window
• C# DevKit extension keep logging Microsoft.VisualStudio.CSharpExtension.BuildResultService not found.
• C# extension log:

Installing C# dependencies...
Platform: linux, x86_64, name=ubuntu, version=20.04

Downloading package '.NET Core Debugger (linux / x64)' Failed to download from https://vsdebugger.azureedge.net/coreclr-debug-2-0-2/coreclr-debug-linux-x64.zip. Error code '409')
Failed at stage: downloadPackage
409

[Error - 11:37:01 AM] Microsoft.CodeAnalysis.LanguageServer client: couldn't create connection to server.

Accessing to the link return me this XML:

<Error>
<Code>PublicAccessNotPermitted</Code>
<Message>Public access is not permitted on this storage account. RequestId:1bd3d9f3-a01e-0059-5966-635d3d000000 Time:2025-12-02T08:33:19.7413606Z</Message>
</Error>

Expected Behavior

C# DevKit extension install the correct C# extension version.
C# extension is able to download required dependencies.

Actual Behavior

Version mismatch and dependencies not availble.

[dibarbet]

2025-12-02 11:33:06.510 [info] The C# extension is installed, but has version 1.23.16 which is incompatible with C# Dev Kit.
Switch C# to pre-release version: automatically install version 2.0.251

These versions of the extension are incredibly old (at least 2 years old). Can you check if the VSCode install on WSL is up to date? The VSCode version you listed in the issue looks like the Windows version and not the version installed on WSL.

[luca-piccioni]

@dibarbet Thanks for the feedback. VSCode is not installed on WSL2, but it is the VS Code installed on Windows that connect to WSL2 using Remote Explorer. I think VSCode will download the very same vscode-server (corresponding to the commit hash) onto WSL2, for Linux/amd64.

Not sure why Extension Manager select extensions versions so old. Shouldn't it select the most recent one (like pre-release check does)?

[dibarbet]

I think VSCode will download the very same vscode-server (corresponding to the commit hash) onto WSL2, for Linux/amd64.

Agreed, but just to confirm may be useful to run code --version from the WSL terminal instance to make sure.

Additionally, from the extensions panel you could try running the "Install Specific Version" item to see if you can install a recent version in wsl:

Otherwise, we don't control acquisition of the extension on our side. you may have to reach out to the actual VSCode folks to understand why it's acquiring a super outdated version of the extension.

[luca-piccioni]

Thanks. After I felt stupid downloading a specific version... because it didn't download anything... I wiped out vscode from Windows and WSL2; updated it; installed DevKit on Windows -> Worked; Then started WSL2 remote connection, installed DevKit... and guess what? It worked like a charrm.

Since C# extension is installed automatically, I supposed that C# DevKit had some references in it.

Probably the error was cause by unfortunate local state.

Thank yo anywway.