List of steps to reproduce
- Upload a file to Commons
- Add a category
- Look into category (thumbnails of files)
What happens?:
Some (but not all) recently uploaded files don't show thumbnails, but only the filename. I've been registering this behaviour for more than a year.
What should have happened instead?:
The file thumbnails should appear in the categories.
Screenshot:
These are mine files uploaded by Pattypan, doesn't matter if I'm logged in/out, browser, OS...
I assume that it can be caused by some caching problems. After purging the server cache, the thumbnails would usually appear.