{"slug": "codex-is-down", "title": "Codex Is Down", "summary": "OpenAI's Codex desktop app (version 26.611.61753) is failing for some Pro subscribers with repeated 'unexpected status 404 Not Found' errors from the chatgpt.com backend, interrupting long-running sessions. A user on a GPT-5.4 xhigh session reported the error three times in a row, while a separate GPT-5.5 xhigh session remained unaffected, and the issue persisted after retries. The user suggests more resilient retry logic with exponential backoff to prevent mid-session failures.", "body_md": "-\n[Notifications](/login?return_to=%2Fopenai%2Fcodex)You must be signed in to change notification settings -\n[Fork 18.6k](/login?return_to=%2Fopenai%2Fcodex)\n\n# unexpected status 404 Not Found: Unknown error, url: https://chatgpt.com/backend-api/codex/responses, cf-ray: ... #28756\n\n[appIssues related to the Codex desktop app](https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22app%22)Issues related to the Codex desktop app\n\n[bugSomething isn't working](https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22bug%22)Something isn't working\n\n[connectivityIssues involving networking or endpoint connectivity problems (disconnections)](https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22connectivity%22)Issues involving networking or endpoint connectivity problems (disconnections)\n\n[sessionIssues involving session (thread) management, resuming, forking, naming, archiving](https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22session%22)Issues involving session (thread) management, resuming, forking, naming, archiving\n\n## Description\n\n**EDIT:** To everyone here, the solution was actually reasonably simple, [just follow these instructions](https://www.youtube.com/watch?v=dQw4w9WgXcQ&list=RDdQw4w9WgXcQ).\n\n### What version of the Codex App are you using (From “About Codex” dialog)?\n\n26.611.61753\n\n### What subscription do you have?\n\nPro x20\n\n### What platform is your computer?\n\nDarwin 25.3.0 arm64 arm\n\n### What issue are you seeing?\n\nRepeatedly encountering in my GPT 5.4 xhigh session:\n\n```\nunexpected status 404 Not Found: Unknown error, url: https://chatgpt.com/backend-api/codex/responses, cf-ray: ...\n```\n\nI can send a message and get an update back, but then when the agent would think and continue I encountered this error 3 times in a row.\n\nI have another session running with GPT 5.5 xhigh and it seems to be unaffected.\n\n### What steps can reproduce the bug?\n\nI have a long running session going, it's had many compactions and plenty of steering. I've also been spinning up sub-agents for smaller tasks where this session is acting as an orchestrator. It failed shortly after steering it to spin up a sub-agent, not sure if that's related.\n\nSession stopped with this error, it retried 5/5 times and gave up. This did not occur immediately after compaction, but it was shortly there after, maybe around 50k tokens.\n\nSending Continue did work, but it failed again after taking a turn. I tried this twice more and it does seem that for now the session is continuing on.\n\n### What is the expected behavior?\n\nDon't die mid session.\n\nIdeally we'd also have more error resistant retries with exponential back-off to something like 20 retries over 10 minutes.\n\n### Additional information\n\n*No response*\n\n## Activity\n\n## Metadata\n\n## Metadata\n\n### Assignees\n\n### Labels\n\n[appIssues related to the Codex desktop app](https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22app%22)Issues related to the Codex desktop app\n\n[bugSomething isn't working](https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22bug%22)Something isn't working\n\n[connectivityIssues involving networking or endpoint connectivity problems (disconnections)](https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22connectivity%22)Issues involving networking or endpoint connectivity problems (disconnections)\n\n[sessionIssues involving session (thread) management, resuming, forking, naming, archiving](https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22session%22)Issues involving session (thread) management, resuming, forking, naming, archiving", "url": "https://wpnews.pro/news/codex-is-down", "canonical_source": "https://github.com/openai/codex/issues/28756", "published_at": "2026-09-03 14:54:31+00:00", "updated_at": "2026-09-03 15:24:51.410808+00:00", "lang": "en", "topics": ["ai-products", "ai-tools", "ai-infrastructure"], "entities": ["OpenAI", "Codex", "GPT-5.4", "GPT-5.5"], "alternates": {"html": "https://wpnews.pro/news/codex-is-down", "markdown": "https://wpnews.pro/news/codex-is-down.md", "text": "https://wpnews.pro/news/codex-is-down.txt", "jsonld": "https://wpnews.pro/news/codex-is-down.jsonld"}}