[BUG] Claude.exe starts process, but no CLI or vscode extension response

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?

Launching claude from either cli or in vscode extension, in both cases claude is unresponsive. Running claude in the terminal launches the process, but there is never a launch of the CLI interface, in the extension, the extension opens, you can submit a prompt, but there is never a response. No errors reported.

I can run claude doctor / update / mcp

I've run claude update several times, restarted everything, rebooted. Nothing changes things.

What Should Happen?

Claude was working until yesterday evening (4/2/26), stopped around 7pm UK time.

Error Messages/Logs

No errors visible. Have run claude doctor which found no errors.

Steps to Reproduce

1. open a terminal (powershell)
2. enter claude
3. watch the blinking cursor
4. ctrl-C to end the pain

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.19

Claude Code Version

2.1.19

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_