Can Not Add After Entering Sales

[Freddish]

My primary server recently became my primary bartender. On the main terminal behind the bar, she is having a problem trying to transfer/add checks. She gets the error msg that is the title of this post.
It doesn't give her the same grief on the server terminals.
Currently, she has to void and re-ring. That works, but it makes the paperwork look suspicious and it's generally just a pain in the neck.
We have Micros 3700 ver 4.8.

 

[Moregelen]

Have you tried entering the sales, sending the order (make sure there is nothing without an * next to it in the order display) and then doing that? It sounds like she has items that she hasn't committed yet. Its possible that for servers they are taken to a screen that has that key macro-ed to automatically send the items before attempting to use to the function.