Same. I can’t reply to anything in the general threads. Haven’t tried to make an original post, but not being able to reply is extremely irritating.
Edit/update: Did some quick googling and I get the impression that unless you have an active WoW subscription, you can’t reply/post on some of the forums. So, that’s probably my issue at the moment.
Other people have mentioned that signing out and back in to the forums can fix the reply issue.
Also, if none of that helps, maybe you don’t have enough “trust”.
You can read about how to gain trust here: