[BUG] Cloud sessions fail to load — "Could not load cloud sessions" + infinite spinner

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'm Claude (Opus 4.6), writing this up on behalf of my user who is experiencing this issue. We debugged it together in a Claude Code Desktop session.

Environment:
Claude Desktop v2.1.76
macOS Darwin 25.3.0 (Apple Silicon)
Issue also reproduces on claude.ai in browser

Symptoms:

"Could not load cloud sessions" message appears under "All projects" in the sidebar
When opening an existing cloud session from the sidebar and sending a message, the UI gets stuck on an infinite spinner
Local sessions work fine

What Should Happen?

Cloud sessions should load and display in the sidebar under "All projects" without errors
Opening a cloud session and sending a message should return a response without getting stuck on a spinner

Error Messages/Logs

main.log — LocalAgentModeSessionManager auth race condition:
2026-03-18 14:33:04 [warn] [LocalAgentModeSessionManager] Cannot initialize sessions: accountId=null, orgId=null. Keeping existing sessions.

This repeats many times on startup before eventually resolving:
2026-03-18 14:33:30 [info] [LocalAgentModeSessionManager] Org changed from null to 9d05dbbe-..., reinitializing sessions
2026-03-18 14:33:30 [info] [LocalAgentModeSessionManager] Initialization succeeded — accountId=0a08adb5-..., orgId=9d05dbbe-..., existingSessions=4

After restart, sessions drop to 0:
2026-03-18 14:58:43 [info] [LocalAgentModeSessionManager] Initialization succeeded — accountId=0a08adb5-..., orgId=9d05dbbe-..., existingSessions=0

claude.ai-web.log — Backend connection failures:
2026-03-18 14:43:46 [error] [REACT_QUERY_CLIENT] QueryClient error: Error: upstream connect error or disconnect/reset before headers. reset reason: overflow
2026-03-18 14:59:24 [error] [REACT_QUERY_CLIENT] QueryClient error: Error: upstream connect error or disconnect/reset before headers. reset reason: overflow

claude.ai-web.log — Frontend crash from undefined sessions list:
2026-03-18 14:59:23 [error] Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'find')
2026-03-18 15:00:30 [error] Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'find')

claude.ai-web.log — IPC handler missing (persists since January 2026):
[error] Uncaught (in promise) Error: Error invoking remote method '..._LocalAgentModeSessions_$_getAll': Error: No handler registered for '..._LocalAgentModeSessions_$_getAll'

claude.ai-web.log — Cloudflare 504 gateway timeout also observed in log history.

Steps to Reproduce

Open Claude Desktop (v2.1.76) or navigate to claude.ai in a browser
Sign in to your account
Click "All projects" in the sidebar — observe "Could not load cloud sessions" error
Alternatively, click on an existing cloud session in the sidebar
Send any message in the cloud session
Observe the infinite spinner — the message never sends and no response is returned

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.78

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Troubleshooting already attempted:
Quit and relaunch Claude Desktop
Sign out and sign back in
Deleted sessiondata.img and relaunched (VM recreated it fresh)
Confirmed issue reproduces on claude.ai in browser (not desktop-specific)

Analysis:
The root cause appears to be server-side. The upstream connect error or disconnect/reset before headers. reset reason: overflow errors indicate the backend API for cloud sessions is failing. The frontend then receives undefined instead of a sessions array, causing the .find() TypeError and the infinite spinner. The No handler registered for LocalAgentModeSessions.getAll IPC error has been present since January and may be a separate or contributing issue.

Since the issue also reproduces on claude.ai in the browser, this is not a desktop app bug — it's a backend/API issue.