[Alfa1]

Thanks. I have been able to recreate this, by following your option C:

c) Create/edit entry, choose the associated forum.

But not with option B, which I would like to use, since it doesn't require members to select a forum:

b) Create/edit category, and choose the associated forum on that menu. If you wish, retro-apply it to all existing entries. That forum will be the default for all new entries in the category

Edit: for some reason members can now only see 4 categories, instead of all. Some categories do not show all files. Moderators and admins see all categories and files without problems. Can this have to do with permissions of a forum getting applied to my total LDM? With trying to use option B above, I set the Parent forum, which in turn applies forum permissions to that category.