[BUG] Task history deleted

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?

Got an error message in claude cowork saying that the prompt was too long and could not be processed (even though it was a shorter prompt than previous tasks). After two error messages like this, my entire task history was deleted, but it came back after 20 minutes or so.

What Should Happen?

Claud should have processed the prompt as it had done before, and my task history should not have been deleted. There should be an easy path to recover the task history when it is gone.

Error Messages/Logs

Prompt too long

Steps to Reproduce

Ask it to analyse 6 word documents with hundreds of pages, and build analyses of content

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Sonnet 4.6

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_