Since OpenAI apparently has no interest in fixing this error (or “functionality”?), I have switched my coding tasks to Gemini. I suggest the same for others with this issue.
Getting this stupid error for every single file I upload.
I easily fixed it by changing browser
it is EMBARASSING that you guys are an AI company that can’t figure out a simple image upload. Just WOW!
Today 05-March-2026, I am facing this same error during uploading programming .php, .css, .ts files while I have cleared cache and cookies but the issue is not solved.
Curious to understand the scope here.
A couple quick questions that would help narrow it down:
- Does this only happen when uploading code files, or do you see the same behavior with other file types as well?
- Are you seeing this inside ChatGPT, or inside a Custom GPT?
If you’re able to reproduce it consistently, the fastest way for us to investigate is through a support ticket, please send the following to support@openai.com:
- A HAR file from the session where the upload fails
- The conversation ID
- The timestamp when the error occurred
- The exact error message, if one appears
That should give the team enough detail to trace what’s happening on the backend.
-Will
- Does this only happen when uploading code files, or do you see the same behavior with other file types as well?
- For me it is just c # classes. the same file I had been using all of sudden wont upload.
- Are you seeing this inside ChatGPT, or inside a Custom GPT?
- Regular Chat GPT in google chrome.
If you’re able to reproduce it consistently, the fastest way for us to investigate is through a support ticket, please send the following to support@openai.com
- N/A
- A HAR file from the session where the upload fails
- N/A
- The conversation ID
- N/A
- The timestamp when the error occurred
- N/A
- The exact error message, if one appears
- ”Unexpected Error” Appears in a red banner at the top center of screen.
same here. can’t upload 50kb php file into browser session. a week ago it was worked fine
error_stack: “UserFileError: Error stream processing upload: indexing failed: file.indexing.error: file.indexing.error\n at FW (…/cdn/assets/4813494d-cnfti3ysfr8w9n5p.js:2:700649)\n at async HP (…cdn/assets/4813494d-cnfti3ysfr8w9n5p.js:2:703607)\n at async Object.uploadFile (…cdn/assets/4813494d-cnfti3ysfr8w9n5p.js:2:1623549)\n at async Promise.all (index 1)”
I am experiencing this error when uploading C# files now. I’ve been using ChatGPT for months and uploading C# files has never been a problem until this week.
I have a specific C# file that never uploads successfully. Every time I try to upload it, I get an “Unknown error” message.
The file is specifically named G.cs. If I rename it first, for example to G.cs_, it uploads without any problem.
I have had this issue for months now.
just happening inside the custom GPT knowledge attachment bar too
I just upgraded to the Pro plan and not even 3 days in i got this problem, “Unknown error ocurred” only for md, json, pdf files. I have used the normal 20$ version for 3 years and never had this problem. I can upoad pictures, txt files and all types of files saved on library including this ones “md, json, pdf files” so it seems it’s a direct problem with the uploading system.
It happens in all types of chats whether is regular chat or Custom Chatgpt.
Something has to be going on because I started having this issue just this evening, I did a google search and found this post, and you just commented the same issue 6 mins ago…
Like you, I’ve been uploading files to gpt for years on the paid version with no issues, but just now it started happening.
Go user. I was working on the project and encountered this error about 30 minutes ago while uploading a PDF (with no image content). I changed browsers, cleared the cache, tried another PDF, reprinted as suggested, deleted the session containing the same PDF, tested with the free version, used the desktop app, and changed the filename, all to no avail. If this continues until the evening, I will have to cancel my subscription.
I know! i did all that too including Incognito and another free account and nothing changed, monthly payment of 120$ for this is a joke. I hope they solve it fast otherwise yeah i will probably look for another option too. If they were fixing something and at least would notify users beforehand i could understand but out of nowhere it’s not ok.