This is a UX bug, methinks, that will cause some confusion on a new forum I am launching next week. See screenshot below - this is for a category where “everyone” is only allowed to see and not post or reply.
There is a “new topic” button and even encouragement at the bottom to post with “there are no more test topics. why not create a topic.”
If you click any of these you can create a topic but only elsewhere, not in this particular category.
Edit: I just realized it’s worse than that. If you try to create a topic in a category you are not allowed to post in, the only category option is “uncategorized” and you can’t contribute to any of the other categories you ARE allowed to post in. This will be a sad, confusing first experience for a newbie to the forum.