[BUG] undefined is not an object (evaluating 'U.length') - crash on session start

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?

Claude Code crashes with undefined is not an object (evaluating 'U.length') in React internals. This happened 3 times in different contexts, always in terminal mode.

What Should Happen?

Session should start normally without crashing.

Error Messages/Logs

ERROR  undefined is not an object (evaluating 'U.length')

  /$bunfs/root/claude:685:20565

  The stack points to minified React code in the DetermineComponentFrameRoot / AT (component stack generation) function.

Steps to Reproduce

No reliable reproduction steps — the crash appears random and not tied to a specific action.

1. Mid-task — crashed while Claude was actively working on a task
2. End of response — crashed right after answering a simple question (no file modifications)
3. On startup — crashed ~30 seconds after launching Claude Code

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

currentVersion: 2.1.32

Platform

Other

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

_No response_