Do you have a copy of the image you were trying to upload? I could check the logs to see what's wrong.
Image uploads seem fine on my end:
Except for some really large (8000x8000) images. I also upgraded to a pre-release of pictrs last night because it fixes this really annoying bug where images appear broken. But it might have introduced other bugs.
The original from this https://yande.re/post/show/253713 I didn't realize the size, but the error is pretty cryptic if that was why. Thanks for checking
That might be the case. I think I can increase the limits that pictrs can accept.
edit: I increased the limits so very high resolution images (up to 8000px) can be uploaded (but are still downscaled to 4096px).
Now, what I can't figure out is why pictrs isn't processing the Haruhi image. Directly uploading the file taken from yande.re doesn't work (it just silently fails). Converting the file to PNG (or any format) and uploading works: