VS Code Claude extension fails with "SyntaxError: Unexpected token 'C'" on clean install

I'm trying to use the Claude Code extension, but it fails to initialize.

Environment:

• Extension: 2.0.13
• VS Code: 1.105.0
• OS: Windows 11 (Windows_NT x64 10.0.26100)

Problem: Immediately after installation, the extension's side panel shows a persistent error: SyntaxError: Unexpected token 'C', "Claude con"... is not valid JSON. This error blocks all functionality. It seems the extension is trying to parse a non-JSON file that starts with "Claude con...".

I expected the extension to load normally after installation. Instead, I got the SyntaxError.

To fix this, I have tried exhaustively:

1. Complete Reinstallation: Uninstalled the extension and manually deleted all related folders in %USERPROFILE%\.vscode\extensions and %APPDATA%\Code\User\globalStorage.
2. Manual mcp.json Creation: Created a valid mcp.json with a correct PAT using a plain text editor to rule out script/encoding issues.
3. Configuration Checks: Confirmed the workspace is "Trusted" and the user settings.json is empty. The error still occurs even with no folder open.
4. Full VS Code Profile Reset: Renamed the entire %APPDATA%\Code folder to launch VS Code in a factory-fresh state. I installed only the Claude Code extension, but the same error occurred immediately.

None of these steps solved the problem. I now suspect the cause is an external factor (a bug specific to my environment or a network issue) rather than a local configuration error.