### Preflight Checklist - [x] I have searched [existing issues](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20state%3Aopen%20label%3Abug) 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? Claude Code Web (claude.ai/code) is completely non-functional on my account since the April 28 outage (17:34–18:52 UTC). Every new session fails during "C

[BUG] Claude Code Web — All sessions destroyed during April 28 outage, account-level server-side corruption

Resolved 💬 5 comments Opened Apr 29, 2026 by RyanWirth Closed Jun 12, 2026

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?

Claude Code Web (claude.ai/code) is completely non-functional on my account since the April 28 outage (17:34–18:52 UTC). Every new session fails during "Cloning repository → Initializing" with:

"An error occurred while executing Claude Code. You can try again by sending a new message or starting a new session."

This reproduces 100% of the time across macOS, Windows, Microsoft Edge, Chrome, incognito mode, and multiple machines. Regular Claude Chat works fine. This is server-side — not local.

Console Evidence

Browser DevTools reveals two problems:

1. All 7 previous sessions were destroyed server-side and the client is stuck polling them in a loop:

[REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01192kx9vDVHCPagM9Gyna6x not found
[REACT_QUERY_CLIENT] QueryClient error: sb: Session session_012ycT36LWkhddnjBPe5v1fo not found
[REACT_QUERY_CLIENT] QueryClient error: sb: Session session_013ptSZAqyomNiAWmUtMhtdL not found
[REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01Jf9MAE15W5tqb4u7dLNDiD not found
[REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01LSrdnsxDnPPZwtEBxD6U5g not found
[REACT_QUERY_CLIENT] QueryClient error: sb: Session session_011AeoCg1SfL134M1w5MQnAW not found
[REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01CyD5gxTJiK9AogUY947w9g not found

All /v1/sessions/{id}/mark_read calls return 404. These errors repeat in an infinite loop.

2. Model config endpoint returns 404 due to malformed model name:

/api/organizations/f908ee70-8231-4203-b01e-10735d5a7fa2/model_configs/claude-opus-4-7[1m] → 404

Note the [1m] — this is a terminal ANSI escape code that got embedded in the model name string server-side.

Troubleshooting Attempted

✅ Fresh sessions (not resuming old ones) — same error
✅ Cleared browser cache, cookies, local storage
✅ Different browsers (Chrome, Edge, incognito)
✅ Different machines (Mac, Windows)
✅ Logged out and back in
✅ Cannot use /feedback because Claude Code won't initialize

What Needs to Happen Server-Side

Purge the 7 dead session references from my account
Fix the corrupted model config string (claude-opus-4-7[1m] → claude-opus-4-7)
Verify git_proxy infrastructure is healthy for this account

Related Issues

This matches the pattern in #22277 and #27856 — server-side git_proxy/session corruption causing 100% repro failures across all platforms.

Environment

Org ID: f908ee70-8231-4203-b01e-10735d5a7fa2
Platform: Claude Code Web (claude.ai/code)
OS: macOS + Windows (reproduces on both)
Browsers: Chrome, Microsoft Edge, incognito
Started: During April 28, 2026 outage (17:34 UTC)

What Should Happen?

The system should connect and work

Error Messages/Logs

API Error
An error occurred while executing Claude Code. You can try again by sending a new message or starting a new session.

[O11Y] [DatadogRUM] Initialized Object
index-B3c1eJ14.js:2 [SERVICE_WORKER] Found 1 service worker(s), which are no longer used. Unregistering.
warn @ index-B3c1eJ14.js:2Understand this warning
/api/organizations/f908ee70-8231-4203-b01e-10735d5a7fa2/model_configs/claude-opus-4-7[1m]:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async index-B3c1eJ14.js:3:74993
error @ index-B3c1eJ14.js:2Understand this error
/v1/sessions/session_01192kx9vDVHCPagM9Gyna6x/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_012ycT36LWkhddnjBPe5v1fo/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_013ptSZAqyomNiAWmUtMhtdL/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01Jf9MAE15W5tqb4u7dLNDiD/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01LSrdnsxDnPPZwtEBxD6U5g/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_011AeoCg1SfL134M1w5MQnAW/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01CyD5gxTJiK9AogUY947w9g/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01192kx9vDVHCPagM9Gyna6x not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_012ycT36LWkhddnjBPe5v1fo not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_013ptSZAqyomNiAWmUtMhtdL not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01Jf9MAE15W5tqb4u7dLNDiD not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01LSrdnsxDnPPZwtEBxD6U5g not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_011AeoCg1SfL134M1w5MQnAW not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01CyD5gxTJiK9AogUY947w9g not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
/api/organizations/f908ee70-8231-4203-b01e-10735d5a7fa2/interviews/ai_for_science:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01LSrdnsxDnPPZwtEBxD6U5g/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_012ycT36LWkhddnjBPe5v1fo/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01Jf9MAE15W5tqb4u7dLNDiD/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01192kx9vDVHCPagM9Gyna6x/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01Jf9MAE15W5tqb4u7dLNDiD/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_012ycT36LWkhddnjBPe5v1fo/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01CyD5gxTJiK9AogUY947w9g/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01192kx9vDVHCPagM9Gyna6x/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01LSrdnsxDnPPZwtEBxD6U5g/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_011AeoCg1SfL134M1w5MQnAW/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01CyD5gxTJiK9AogUY947w9g/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_013ptSZAqyomNiAWmUtMhtdL/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_011AeoCg1SfL134M1w5MQnAW/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_013ptSZAqyomNiAWmUtMhtdL/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01LSrdnsxDnPPZwtEBxD6U5g not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_012ycT36LWkhddnjBPe5v1fo not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01Jf9MAE15W5tqb4u7dLNDiD not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01192kx9vDVHCPagM9Gyna6x not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01Jf9MAE15W5tqb4u7dLNDiD not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_012ycT36LWkhddnjBPe5v1fo not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01CyD5gxTJiK9AogUY947w9g not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01192kx9vDVHCPagM9Gyna6x not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01LSrdnsxDnPPZwtEBxD6U5g not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_011AeoCg1SfL134M1w5MQnAW not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01CyD5gxTJiK9AogUY947w9g not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_013ptSZAqyomNiAWmUtMhtdL not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_011AeoCg1SfL134M1w5MQnAW not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_013ptSZAqyomNiAWmUtMhtdL not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
frame-modern.f7ff4520.js:1 [Intercom] Launcher is disabled in settings or current page does not match display conditions
index-B3c1eJ14.js:23 ProseMirror expects the CSS white-space property to be set, preferably to 'pre-wrap'. It is recommended to load style/prosemirror.css from the prosemirror-view package.
(anonymous) @ index-B3c1eJ14.js:23Understand this warning
/v1/sessions/session_01192kx9vDVHCPagM9Gyna6x/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_013ptSZAqyomNiAWmUtMhtdL/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01Jf9MAE15W5tqb4u7dLNDiD/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_01CyD5gxTJiK9AogUY947w9g/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
/v1/sessions/session_012ycT36LWkhddnjBPe5v1fo/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01192kx9vDVHCPagM9Gyna6x not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_013ptSZAqyomNiAWmUtMhtdL not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01Jf9MAE15W5tqb4u7dLNDiD not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01CyD5gxTJiK9AogUY947w9g not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_012ycT36LWkhddnjBPe5v1fo not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
/v1/sessions/session_011AeoCg1SfL134M1w5MQnAW/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_011AeoCg1SfL134M1w5MQnAW not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)
error @ index-B3c1eJ14.js:2Understand this error
/v1/sessions/session_01LSrdnsxDnPPZwtEBxD6U5g/mark_read:1  Failed to load resource: the server responded with a status of 404 ()Understand this error
index-B3c1eJ14.js:2 [REACT_QUERY_CLIENT] QueryClient error: sb: Session session_01LSrdnsxDnPPZwtEBxD6U5g not found
    at ab (index-B3c1eJ14.js:2:175710)
    at index-B3c1eJ14.js:3:73718
    at async Object.mutationFn (index-B3c1eJ14.js:3:74443)

Steps to Reproduce

The only thing I can do Is log in and and then it gets stuck with my account.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

4/27/2026

Claude Code Version

Opus 4.7 1M

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

View original on GitHub ↗

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