[BUG] Claude Code VS Code Extension Crashes on Startup - Host Extension Unexpectedly Closed

[wellfitness]

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• I am using the latest version of Claude Code

What's Wrong?

he Claude Code VS Code extension crashes within seconds of starting up, displaying the message "host extension unexpectedly closed." The extension becomes unresponsive and requires restarting VS Code.

What Should Happen?

The extension should load successfully and remain stable, allowing normal interaction with Claude Code through the VS Code interface.

Error Messages/Logs

The host server terminated unexpectedly

Steps to Reproduce

1. Open VS Code with Claude Code extension installed
2. Click the Spark icon in the sidebar to open Claude Code panel
3. Extension starts loading
4. Within a few seconds, extension crashes with "host extension unexpectedly closed" message
5. Extension becomes non-functional

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.0.0

Claude Code Version

2.0.10

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

Troubleshooting Steps Attempted

• Restarted VS Code multiple times
• Disabled other extensions to check for conflicts
• Cleared extension data/cache
• Reinstalled Claude Code extension

Additional Context

The extension worked previously but started crashing recently. The issue appears to be specifically related to conversation history loading, as the crash occurs during the initial loading phase.

Feature Request

If possible, could you provide an option to disable conversation history loading on startup, or implement lazy loading for conversation history to prevent startup crashes?

[Kaiser9005]

Have the same issue !

[theverex]

Also have the same issue.

[wellfitness]

Does it happen to you in all VS Code projects?

Outside the project folder, I can launch the extension and work with the project files. If I start the extension inside the Next.js project folder, it breaks Next.js, so I only use the command line terminal there.

[theverex]

Does it happen to you in all VS Code projects?

Outside the project folder, I can launch the extension and work with the project files. If I start the extension inside the Next.js project folder, it breaks Next.js, so I only use the command line terminal there.

Yes it happens when I open a VScode folder and then use the tab. The claude terminal works fine even from VScode, its just the extension that causes crashes.

[Deekow]

Same issue, and terminal also works, but IDE is a non-starter now.

[Deekow]

I was able to resolve this by deleting everything in the project folder (c:\Users\ -my folder- .claude\projects). I had to reauthenticate in terminal, but then it worked in IDE. This is a very heavy solution, and absolutely no warning that this would be required, and the Claude help desk AI had no recommendation of this. This shouldn't be the required solution either.