Problem with TR posting

I get the following message when attempting to post to the self trained discussion.

Sorry for the inconvenience, but an error has occurred in our system trying to post your new message

In fact, I cannot see all the posts. For example Apotheon posted today 6/14 several messages. I can tell because I have Apotheon as a contact and can read the posting that way, but I cannot find it in the discussion threads because it doesn’t show up there.

Don’t know if that made sense, but can someone explain this? thanks