Can't upload news article with image

[danieladugyan]

Description

I tried to publish an article with an image, but it didn't work even though I tried multiple times.
original source: in-person bug report

Steps to reproduce

Step 1. Go to https://www.dsek.se/news/create.
Step 2. Add an image.
Step 3. Try to publish the article.

Further information

It works sometimes so I'm guessing this has something to do with the image, probably its size. If that's the case, make sure the error message reflects that clearly.