Three possibilities:
1. As the previous poster has said the thread has been closed. Hints for this is that they close automatically at 175 posts, or have been closed by the admins for some reason.
2. You have received a time out for transgression of some vague rule or complaint.
3. The thread is being moved from one forum to another because it was created in the wrong forum - usually happens when people create posts in the FabGuys site feedback forum that are nothing to do with site feedback (as with many other things on here, just because you can doesn’t mean you should).