[BUG] Claude Code crashes when reading/writing a file that is being modified by external process (e.g., node file watcher)

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?

happen quite often, it will 100% crash the same point if re-try. crash 5 times in a row, until I ask claude to try something else.

• - - Issue: Claude Code crashes when reading/writing a file that is being modified by external process (e.g., node file watcher)
• Reproduction: Have a dev server running with hot-reload, attempt to edit a watched file
• Expected: Graceful error handling
• Actual: Repeated crashes, context loss

What Should Happen?

not crash no matter what.

Error Messages/Logs

Steps to Reproduce

i dont know how, this is during my project.

Root Cause Analysis

1. File was being modified externally - Most likely a running node process with hot-reload/file watcher was modifying the file between my read and

write operations

1. I didn't kill the node processes first - The command taskkill //F //IM node.exe was attempted but may not have completed before I tried reading

again

1. I kept retrying the same approach - Instead of:

• Waiting for the kill to complete
• Reading in smaller chunks
• Checking if any process was locking the file

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

Claude Code v2.0.55 Opus 4.5 · Claude Max

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_