I'm trying to do a delete query to delete certain orders from an order table. I created the delete query by linking the order file to another file called on hold (a file showing all order number on hold) and
then saying delete all orders that match. The error I got was "operation must use an updatable query." Not sure why.

I'm not sure if this will work - but I think I had the same problem and made a change in the QUERY properties...

open the Q properties and Make "Unique Records" = Yes

Good Luck!