@010101 I was able to reproduce this, not sure what the issue is just yet but we'll get back to you once we find a root cause π
Edit: Are you sure that the add attachment for Flagrow's Upload extension works with Gamification disabled?
Edit 2: Please provide a copy the image or filetype you were trying to upload. Even with Gamification disabled I was only able to reproduce an error with Flagrow/Upload when using ridiculously large images.
The dimenion of the image I tried uploading was 6800x3800
(755kb image) and Flagrow/Upload did not like that.
I can safely conclude that this is NOT problem with our extension until you provide me with some examples that I can personally test. Smaller dimension-ed images get uploaded without any issues on my end, but 4K images such as this one almost instantly presents an error upon attachment.
I will open an issue on Flagrow's Upload extension repo so that this issue that might be related to yours can be further investigated.