For a picture I want to upload on last version of Discourse, max_image_size_kb and max_attachment_size_kb both at 4096, event if I set 20000 Kb, my picture (jpg) is 1.2Mo and I have this error:
Sorry, this file is too large (the maximum size allowed is 4096 KB).
Unless you can reproduce it here, this is a configuration problem with your instance. 4MB is the default upload limit in Discourse.
The most common cause of this issue is a reverse proxy that is not configured properly.
I had exactly the same problem, but setting client_max_body_size in my reverse proxy fixed this.
But the error message displayed is misleading, because it tells the user the value set in max_image_size_kb and not the setting that is causing the problem. Maybe this could be changed to a better wording.
Same happens to me, the error message confuses further instaed of trying to help. Please improve the error message, make it actionable.
Sorry, that file is too big (maximum size is 50 MB). Why not upload your large file to a cloud sharing service, then paste the link?
… and I’m uploading a file between 10 and 20 mb.