This bug happens when you attempt to add any sort of link to your post, it gives you a 403 forbidden error. There’s not much detail to give here other than that.
This bug first to occurred to me on 1/5/23
I can’t provide screenshots as it won’t let me upload images either.
To reproduce this bug, create a new topic, add any link in it, and try to publish it. You will end up getting a 403 forbidden popup. Even GitHub isn’t allowed.