[BUG] Claude Desktop (Windows): Conversation silently lost after apparent app crash — no local or server-side trace

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?

Preflight Checklist

• [x] I am on the latest version of Claude Desktop

What happened?

During an extensive Claude Desktop conversation (~1.5 hours, many messages exchanged), the app appears to have silently crashed or restarted. After the restart, the entire conversation disappeared — it is not visible in the sidebar, not returned by search on claude.ai, and not findable by scrolling through the conversation list.

A forensic investigation of all local storage confirmed the conversation's UUID was never persisted:

• IndexedDB (chat drafts): Only contains drafts for the conversations before and after the missing one
• Session Storage (message timestamps): Shows zero activity during the entire 1h48m window — a complete gap between 10:09 and 11:57
• HTTP/Network cache: No trace of conversation data
• Browser history (Comet): Confirms a Reddit page was visited at 11:45 during the conversation, but no claude.ai navigation
• Service Worker cache: Stale data from August 2025

The conversation before and after are fully intact. Only the one during the crash window is gone.

Claude model

Not applicable (affects the client app, not the model)

Is this a regression?

Unknown — first time experiencing this

Claude Code version

This is Claude Desktop (Windows Electron app), not Claude Code CLI.

API platform

Anthropic first-party (claude.ai)

What OS are you seeing this on?

Windows 11 Home, Build 26200.6899

Terminal

Not applicable (Claude Desktop, not CLI)

What platform are you seeing this on?

Desktop (Electron app)

What Should Happen?

Conversations with exchanged messages should persist on claude.ai servers regardless of client-side crashes. At minimum, conversations that received server responses should be recoverable.

Error Messages/Logs

No crash dialog was shown. Relevant log entries from `claude.ai-web.log` around the time the app restarted:


2026-02-24 11:57:18 [error] [MCP] Could not connect to MCP server mcp-registry Error: Error invoking remote method 'connect-to-mcp-server': Error: Already connected to a transport. Call close() before connecting to a new transport, or use a separate Protocol instance per connection.
2026-02-24 11:57:18 [error] [MCP] Could not connect to MCP server Claude in Chrome Error: ...same error...
2026-02-24 11:58:10 [error] [MCP] Could not connect to MCP server mcp-registry Error: ...same error...
2026-02-24 11:59:12 [warn] ProseMirror expects the CSS white-space property to be set...


Session Storage shows map-426 (last at 10:09) jumping to map-427 (at 11:57) — confirming the app restarted with no intermediate sessions.

Steps to Reproduce

This appears to be a rare crash condition. The general scenario:

1. Open Claude Desktop on Windows
2. Have an active conversation with many messages over ~1-1.5 hours
3. App crashes silently (no error dialog, no crash report prompt)
4. App restarts
5. The active conversation is gone from the sidebar and search

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Version 1.1.4010 (da63f3) (Claude Desktop)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Adjacent conversations (for server-side lookup):

• Before: 43b9e4c3-3598-4e3f-9cc3-ab87edd952d3 (last message ~10:09 CET)
• After: 797df775-dff0-4a8e-9e48-da655d4ccc8c (started ~12:00 CET, titled "Missing reddit conversation")

Conversation content: The missing conversation discussed ADHD strategies and Reddit posts related to an expat relocation project. The user visited r/expats at 11:45 CET during the conversation.

Impact: The conversation contained important, extensive discussion that cannot be recreated. This represents data loss from a client crash — server-side data should be resilient to client failures.