Custom GPTs with Knowledge files incorrectly trigger file upload limit
I am getting a “file upload limit” error when using Custom GPTs with preloaded Knowledge files, even though I have not uploaded any files or images.
The issue started around August 20–21, 2026, shortly after the August 19 ChatGPT outage.
Actual behavior
When I use a Custom GPT that has Knowledge files provided by its creator:
I start a normal text-only conversation. I send a few messages. After a few messages, ChatGPT blocks the conversation and shows:
“You’ve reached our limit of file uploads. Please try again later.”
I have not uploaded any files or images in these conversations.
The same thing happens with multiple different Custom GPTs that have preloaded Knowledge files.
What does NOT trigger the issue
A normal text-only GPT/conversation without Knowledge files continues to work normally.
I reproduced it across multiple environments
This is not limited to one account, device, or app version:
2 different ChatGPT accounts → both affected 2 different devices → both affected Updated Android app → affected ChatGPT web → affected Multiple Custom GPTs with preloaded Knowledge files → affected No user-uploaded files or images → still affected
This makes an account-specific upload quota, device problem, or outdated app version seem unlikely.
Expected behavior
A text-only conversation should not be blocked by a file-upload limit when the user has not uploaded any files.
If Custom GPT Knowledge files are intentionally counted toward the user’s file-upload quota, could OpenAI clarify how this works? In particular, it would be useful to know whether files uploaded by the GPT creator as Knowledge are now counted against each individual user’s upload limit.
Otherwise, this appears to be a false file-upload-limit error involving Custom GPT Knowledge/file handling.
Timing
I first noticed this around August 20–21, 2026, shortly after the August 19 ChatGPT outage.
I would appreciate it if others could test a Custom GPT with Knowledge files and report whether they can reproduce this.
Reproducibility: high — multiple GPTs, accounts, devices, and both web/app.
Additional Finding:
“The GPT also referred to its Knowledge files as ‘2 files you uploaded in this conversation,’ even though I had not uploaded any files. I am not sure whether this wording is expected, but combined with the upload-limit error, it may be relevant.”