Codex App hang by pasting “\n” character
Resolved 💬 7 comments Opened Jun 4, 2026 by joecklau Closed Jun 11, 2026
💡 Likely answer: A maintainer (github-actions[bot], contributor)
responded on this thread — see the highlighted reply below.
What version of the Codex App are you using (From “About Codex” dialog)?
Version 26.601.21317 • Released Jun 3, 2026
What subscription do you have?
Pro
What platform is your computer?
Windows 11 x64 (Microsoft Windows NT 10.0.26200.0 x64)
What issue are you seeing?
Codex App hang, text flow outside Codex App UI window, App frozen that need to be killed.
What steps can reproduce the bug?
Paste this text to any Codex App Chatbox:
PS D:\repo> uv run python -m some.script `
>> --timeout-seconds 10 `
{
"status": "ok",
"failure_reason": null,
"body_preview": "{\n \"experiments\": [\n {\n \"experiment_id\": \"242\",\n \"name\": \"helloworld\",\n \"artifact_location\": \"mlflow-artifacts:/242\",\n \"lifecycle_stage\": \"active\",\n \"last_update_time\": 1780328192676,\n \"creation_time\": 1780328192676\n }\n ],\n \"next_page_token\": \"eyJvZmZzZXQiOiAxfQ==\"\n}"
}Then Codex App will be frozen.
What is the expected behavior?
The Codex App should work normally
Additional information
I tested that the key part seems to be the json line with "\n" character. If I paste without the line with "\n", it still has a small lag at the time I paste, but it won't be frozen.
7 Comments
Potential duplicates detected. Please review them and close your issue if it is a duplicate.
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They are also json related but not exactly same cause. Unlike the json
length of those issues, the cause of hang here I pin-pointed here is “\n”
character in pasted json.
「github-actions[bot] @.***>」2026-06-04：
I believe I'm running into this as well but with latest macos app v26.601.21317 (3511). Will update with more details if I find any soon, but now it also freezes whenever I open the app (just a white window) since I believe it is trying to load a draft with pasted text (perhaps with \n). In activity monitor it reports that "Codex (Rendered)" is at ~100% cpu)".
EDIT: Reinstalling codex app and computer restart does not work. Removing ~/.codex folder seems to do the trick however. I also cleared keychain access entries for codex and openai but was likely not needed.
EDIT 2: Tried pasting the text that froze codex the last time and it froze again.
EDIT 3: Issue title says "\n" character but for me it hangs even with no \n character. When pasting a shorter message on the same format as above (just first half for example) the renderer process also goes crazy at 100% cpu but you can still edit text but very slowly and laggy so my best guess is that it tries to parse the text in some way but that it gets expensive due to a bunch of \ and " etc.
jxj@MacBook-Pro ~ % curl "$BASE_URL" \
-H "Content-Type: application/json" \
-H "Authorization: Bearer $API_KEY" \
-d '{
"model": "'"$MODEL"'",
"messages": [
{"role": "user", "content": "请先认真思考，再回答 13*17 等于多少。"}
],
"thinking": {"type": "disabled"}
}'
{"choices":[{"finish_reason":"stop","index":0,"logprobs":null,"message":{"annotations":null,"audio":null,"content":"\n\n我已经认真思考过了，13 × 17 = 221。","function_call":null,"reasoning":"The user asks in Chinese: \"请先认真思考，再回答 1317 等于多少。\" Means \"Please think carefully first, then answer: what is 1317?\" The answer is 221. Indeed, 1317 = (1310) + (137) = 130 + 91 = 221.\n\nThe user request is trivial and permissible. There's no policy violation. Should answer.\n\nWe must produce answer in Chinese (the user used Chinese). Provide the result: 221. Possibly also show reasoning: 1317 = 221.\n\nWe can answer succinctly: \"13*17 = 221\".\n\nWe can also follow the instruction: \"请先认真思考，再回答\". So we might say something like \"我已经认真思考过了，13乘以17等于221。\"\n\nThat's it.\n\nNo policy issue. Should answer.\n","refusal":null,"role":"assistant","tool_calls":[]},"routed_experts":null,"stop_reason":null,"token_ids":null}],"created":1780558708,"id":"chatcmpl-da0a6d98-419b-9930-977e-86b3abf8da59","kv_transfer_params":null,"model":"internal/minimax-m2-5-public-minimax-m25-335bd0a9","object":"chat.completion","prompt_logprobs":null,"prompt_routed_experts":null,"prompt_text":null,"prompt_token_ids":null,"service_tier":null,"system_fingerprint":null,"usage":{"completion_tokens":196,"prompt_tokens":52,"prompt_tokens_details":{"cached_tokens":0},"total_tokens":248}}%
I pasted the above content into the Codex app's input box, and the entire Codex app froze — completely unresponsive. Even after force-closing Codex and relaunching it, other tasks work fine, but as soon as I click into that specific task, the whole app freezes again. That task is basically a dead zone now, and I have to start the work over from scratch. This bug is pretty serious.
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The situation has gotten even worse. I restarted the Codex app 3 times, and every single time, clicking into that task causes the app to freeze. And now when I launch Codex, the entire app just shows a white screen — I can't get in at all — and my computer is running really hot.
<img width="3024" height="1770" alt="Image" src="https://github.com/user-attachments/assets/42128925-d145-4574-80c8-b26ede08b6c6" />
Checked
Version 26.608.12217 • Released Jun 9, 2026bug fixed. pasting same json-containing text with "\n" does not hang Codex App now.