Usually that error is the "filter" not liking a particular word. Looking at your screen shot can't see one that stands out but I suspect there is something it is catching probably out of context but again usually that what causes that error message.
All interceptors for wording will start with "Woah!" and a number so we can figure out which one is getting caught.
Not being able to reply to posts is related to a quirk with Yahoo (OpenID) authenticated accounts. Something weird happens sometimes where either the user doesn't enter a "name" in their Yahoo account or it doesn't sync over. The forum software then validates a few things when a user posts and if it doesn't see the "name" field populated it starts to freak out and throws out an error message. We've got it in the bug list for the vendor already.
Anywho, I fixed it for dark_ram81 by going in on our side and just putting in his username as his name so he should be good to post now.
dark_ram81 - We're in the process of making a lot of changes behind the scenes out here, especially around mobile friendly, we are a mobile company afterall. In this case, what would be your ideal path for reporting this? What would you like to see happen? ("It just works" would be my first preference obviously).