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How to Fix “Microsoft.CodeAnalysis.LanguageServer client: couldn’t create connection to server” Error in Visual Studio Code on macOS

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If you’re using Visual Studio Code (VS Code) on a Mac and have the “C# Dev Kit for Visual Studio Code” plugin installed, you might encounter the error “Microsoft.CodeAnalysis.LanguageServer client: couldn’t create connection to server.” This error typically appears when starting up VS Code, interrupting your workflow and potentially causing frustration. In this post, we’ll explore the cause of this error and provide a couple of solutions to resolve it.

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Error Description

The exact error message you might see is:

Plaintext
Microsoft.CodeAnalysis.LanguageServer client: couldn't create connection to server

Error: Timeout. Client cound not connect to server via named pipe
    at Function.<anonymous> (.vscode/extensions/ms-dotnettools.csharp-2.39.29-darwin-x64/dist/extension.js:2:1264583)
    at Generator.next (<anonymous>)
    at s (.vscode/extensions/ms-dotnettools.csharp-2.39.29-darwin-x64/dist/extension.js:2:1253076)

This error usually occurs right after launching VS Code, particularly if you have multiple windows open or if VS Code is trying to load a large number of extensions simultaneously.

Cause of the Error

The root cause of this error is often related to the “C# Dev Kit for Visual Studio Code” plugin not having enough time to initialize when VS Code starts. When multiple windows or extensions are trying to load at the same time, the language server may fail to establish a connection, resulting in the error message.

Solution

There are a couple of ways to resolve this issue:

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Solution 1: Restart VS Code with Fewer Open Windows

The first and simplest solution involves restarting VS Code after closing all open windows:

  1. Close All VS Code Windows: Before restarting VS Code, make sure to close all open windows. This reduces the load on VS Code and ensures that fewer resources are being used when it restarts.
  2. Restart VS Code: Once all windows are closed, restart VS Code. This time, it should start up with fewer windows and extensions to load, giving the “C# Dev Kit” plugin enough time to initialize properly.
  3. Verify the Fix: After restarting, open your project or any C# file to ensure that the plugin is working correctly and that the error no longer appears.

Solution 2: Increase Dotnet Server Start Timeout

  1. Extend Timeout: Open user settings and search for “Dotnet › Server: Start Timeout”. Increase this value from 30000 (30 seconds) to something longer. I chose 120000.
  2. Restart VS Code: Restart and more time is give to the language server connection.

Solution 3: Reinstall the Plugin

If restarting VS Code doesn’t resolve the issue, another potential fix is to reinstall the “C# Dev Kit for Visual Studio Code” plugin:

  1. Uninstall the Plugin: Go to the Extensions view in VS Code, search for the “C# Dev Kit,” and uninstall it.
  2. Restart VS Code: After uninstalling, restart VS Code to ensure all related files are cleared.
  3. Reinstall the Plugin: Search for the “C# Dev Kit for Visual Studio Code” in the Extensions view and reinstall it.
  4. Verify the Fix: Once reinstalled, open a C# file to check if the error is resolved.

Verification

To verify that the error has been resolved, follow these steps:

  • Open a C# File: Once VS Code has restarted or the plugin has been reinstalled, open a C# file in your project.
  • Check for Errors: Ensure that the error message does not reappear.
  • Test Functionality: Use the C# Dev Kit features, such as IntelliSense or debugging, to confirm that everything is functioning as expected.

Conclusion

The “Microsoft.CodeAnalysis.LanguageServer client: couldn’t create connection to server” error can be frustrating, but it can be resolved with a few simple steps. Whether by restarting VS Code with fewer windows open or by reinstalling the plugin, you can restore your development environment to full functionality. If you continue to experience issues or have additional insights, feel free to leave a comment below!

Tags/Keywords

  • Visual Studio Code
  • macOS
  • C# Dev Kit
  • Language Server
  • VS Code Error
  • Plugin Initialization
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