Found a strange error (which should be friendlier/more understandable to the user) when I do the following:
- Login to a dummy user
- Go to a post in a (private, if related) category where you are not allowed to create topics
- On that post > Reply as topic
- Fill title and post (leave category on default)
- Error pup-up: You may not view the requested resource.
The category field will default to the category where the user is not allowed to create topics. Now this is not a real problem, but at least it should say something like “You are not allowed to post in this category” or even better, if set, show Banner text when a user cannot create a topic in this category: from category settings.