[BUG] VSCode Extension fails to load with ServiceWorker error when ~/.claude/projects folder doesn't exist

Preflight Checklist

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

What's Wrong?

The Claude Code VSCode extension fails to load with a ServiceWorker registration error. The webview remains blank and displays the error:

Error loading webview: Error: Could not register service worker: InvalidStateError: Failed to register a ServiceWorker: The document is in an invalid state..

<img width="717" height="123" alt="Image" src="https://github.com/user-attachments/assets/1d2f3802-917e-4441-8b25-225b3e8e144c" />

After debugging, I found two issues:

1. Missing projects folder: The extension tries to scandir on ~/.claude/projects/ which doesn't exist. The folder was never created during installation.

1. Corrupted Service Worker cache: The %APPDATA%\Code\Service Worker folder contained corrupted cache data.

Workaround:

1. Create the missing folder: mkdir "$env:USERPROFILE\.claude\projects"
2. Close VSCode, delete %APPDATA%\Code\Service Worker, restart VSCode

What Should Happen?

The extension should:
1. Automatically create `~/.claude/projects` folder if it doesn't exist during initialization
2. Handle missing project subdirectories gracefully without crashing
3. Not leave the webview in an unrecoverable ServiceWorker error state

Error Messages/Logs

[Extension Host] rejected promise not handled within 1 second: Error: ENOENT: no such file or directory, scandir 'C:\Users\sample_user\.claude\projects\c--Users-sample_user-dev-sample-project'

[Extension Host] stack trace: Error: ENOENT: no such file or directory, scandir 'C:\Users\sample_user\.claude\projects\c--Users-sample_user-dev-sample-project'
	at async readdir (node:internal/fs/promises:958:18)
	at async t.performRefresh (c:\Users\sample_user\.vscode\extensions\anthropic.claude-code-2.1.5-win32-x64\extension.js:17:7322)
	at async t.load (c:\Users\sample_user\.vscode\extensions\anthropic.claude-code-2.1.5-win32-x64\extension.js:17:7148)

[Anthropic.claude-code] ENOENT: no such file or directory, scandir 'C:\Users\sample_user\.claude\projects\c--Users-sample_user-dev-sample-project'

Webview fatal error: Error: Could not register service worker: InvalidStateError: Failed to register a ServiceWorker: The document is in an invalid state..

Error loading webview: Error: Could not register service worker: InvalidStateError: Failed to register a ServiceWorker: The document is in an invalid state..

Steps to Reproduce

1. Fresh install (or reinstall) Claude Code VSCode extension v2.1.5
2. Ensure ~/.claude/projects folder does NOT exist (only ~/.claude/ide exists)
3. Open any project in VSCode
4. Click the Claude Code icon to open the panel
5. Extension fails to load with ServiceWorker error and blank webview

Environment:

• Windows 11
• VSCode (latest stable)
• Claude Code Extension v2.1.5

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.5

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Suggested Fix:

Add defensive initialization code in the extension:

const projectsDir = path.join(os.homedir(), '.claude', 'projects');
if (!fs.existsSync(projectsDir)) {
  fs.mkdirSync(projectsDir, { recursive: true });
}

Notes:

• The ~/.claude/ide folder was correctly created by the extension
• Only the projects folder was missing
• This appears to be a missing initialization step during extension setup