I know there are other posts addressing this issue, but they don't quite fit. I'm only testing (which is why my restrictions seem over-tough), but the scenario is:
I have three Groups - A, B, C (all have 'no' on ALL options showing in Group Manager). I want to prevent, for example, Group C from being able to create albums in one or more categories (ideally all - one thing at a time) - I've already sorted stopping them uploading files.
I go to Category Manager and 'Edit' a category. The option 'Group(s) allowed to create albums in this category' has a dropbox listing Groups A, B and C. But I can see no way of deleting one or more entries from this list (in this scenario Group C)- the Help talks about clicking and CTRL, which selects (highlights), but nothing removes them.
I have an uneasy feeling that I'm missing something really obvious - am I?
Incidentally, I've only just found Coppermine (1.5.30). I'm very impressed so far.