[BUG] New sessions stuck on "Coalescing..." - only existing sessions work

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?

Creating a new session on Claude Code web gets stuck on "Coalescing..." indefinitely
This happens on all repositories, not just a specific one
Previously created sessions continue to work normally
Browser: windows11
Started happening: 2026-03-17

What Should Happen?

A new session should start normally and Claude should be ready to accept prompts.

Error Messages/Logs

No error messages displayed. The UI shows "Coalescing..." indefinitely and never completes loading. No response is generated.

Steps to Reproduce

1. Open Claude Code Web (https://claude.ai/code)
2. Select any repository
3. Click "+ 新規セッション" (New Session) to create a new session
4. The UI shows "Coalescing..." indefinitely and never loads
5. Previously created sessions continue to work normally
6. This affects all repositories, not just a specific one

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.77 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

_No response_