[BUG] Claude.ai chat history loss

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?

I am as of the past 3 days experiencing chat history loss forcing me to export data for the conversations.json to import into a new chat and provide files for my project split into 30 MB multi-part archive zips, and then prompt Claude.ai to extract, read a file/folder structure tree and continue.

This issue seems to have been reported but was closed. It needs to be fixed immediately!

https://github.com/anthropics/claude-code/issues/14225

Note; I am.not using Claude Code, this is happening with a free account using Sonnet 4.6.

Plus, I keep getting Claude's response could not be fully generated messages. It's broken, and losing the chat history is dire!!!

HELP!!!

What Should Happen?

Claude.ai should NOT lose chat history, at all!

Error Messages/Logs

Steps to Reproduce

Simply run Sonnet 4.6 in a free account with chats in a project. It will fail and you lose chat history.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

N/A

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_