Hi,
I got a problem with some dummy users on our forum. The first category in list when you post a new question is a container. When you hit ask a question this category container is selected by default even if it's impossible to post in it.
When user don't change this value and click on post nothing happens (no error message). I think the default element in the lit should be "select category" not the first one.
https://www.joomunited.com/support/pre-sales-forum/ask
Cheers,