If you use QuarkXPress and upgraded to El Capitan, you will be only too painfully aware that the pair were horribly incompatible, rendering QuarkXPress 2015 and previous versions unusable.

QuarkXPress 2015 version 11.2, available from here, fixes those problems and many other bugs. It is a free update for 2015 users.

However version 10 and previous releases are not going to be fixed: the only route is to upgrade to 2015, version 11, I am afraid.