[BUG] C# DevKit not loading after installing 9.0.100

[rachelkang]

Describe the Issue

After installing .NET 9.0.100, I've been having trouble with the following:

• Creating a new .NET project - the command appears in command palette and the Explorer, but clicking on it fails to do anything
• Loading an existing .NET project - solution explorer, launch menu, and other C# Dev Kit things do not load, and I can't load/run any projects that were previously successful

This admittedly may be unrelated, but I have been having issues regardless.

Steps To Reproduce

No response

Expected Behavior

C# Dev Kit loads, .NET projects can be created and loaded, and everything works as usual

Environment Information

Tried on both the latest release and prerelease versions

[Michael-Eng]

@rachelkang can you please share more context - did you install .NET9 runtime or .NET9 SDK? What do you see in the output window?

[lifengl]

@rachelkang, can you tell us your working environment, whether you are using Windows/Mac/Linux, and the version of the OS, hardware etc. Also the C# DevKit output would help to get some basic/initial understanding of the problem.

also open a command shell, and make sure goes to the root of your workspace, and run dotnet --info, and paste the result. It would provide some information as well.

Note, in some Linux environments, installing SDK from two different venders might corrupt the environment as they might handle symbol links in incompatible ways, which would requite you to remove everything manually and reinstall everything from one vender from scratch. Without proper information from you, we would not be able to investigate your report any further.

[rachelkang]

Hello - I am no longer experiencing this issue after deleting all my workloads and reinstalling just 9.0.100.

For context, it turned out to be caused by installing an internal version of 9.0.100 prior to public release - something got wonky there and made it incompatible with C# Dev Kit. This was from a Mac Sequoia 15.1.

[github-actions]

@Michael-Eng, the 'needs-more-info' label has been removed upon receiving further response from the original bug filer.

[Michael-Eng]

Thanks for the response. Internal versions of .NET require you to turn on workingWithTestSignedSdk in VS Code to allow you to use prerelease versions of .NET.

[lifengl]

@rachelkang : thanks to provide the update for this issue. Just to help to run into this problem: an internal version of the SDK is often developer signed, instead of real signed. Without a proper stamp from Apple, it would not work with C# DevKit by default. The DevKit did have some workaround for that earlier, but Apple's security layer is not fully documented and changes from updates to updates, so the workaround stopped working. There are still manual steps to work around the issue (basically force Mac to trust some of the downloaded SDKs), but not a straight forward thing to do, and it requires the developer on Mac to do that.

[rachelkang]

good to know for future context! thanks for the info