Multiple times, I’ve tried to create a new category, but I always ended up with the warning that someone had supposedly been editing it at the same time. Thought it’d be best to inform about this bug so that it doesn’t go unnoticed.
Topic on User talk:Les
Which categories were these?
Arthropods
The exact same thing is happening to me. It wouldn't let me create any more sandboxes, and sometimes even prevented me from looking at different page revisions.