big problem ( challenge )

what is going on here? i mate these posts to the floor and rail so they are fully defined. i then try move a post to check it is unmovable. it doesnt move. fine. i then hit ctrl q and it comes up with a list of errors as long as my arm. ( see video). bearing in mind i had the whole thing nearly done when this started and i went as far as to delete all the posts and start again, but no luck. is it a bug, or what?

please help someone, or someones going to get hurt!