Deleting a concept which in use should give a more user friendly error message

When i delete a concept which is already in use, i get an "Internal Error Occured" message with a "DataIntegrityViolationException" exception which may not be undestood by all users. This has been reported for other types of delete and i think we should check to see that any screen having data deletion should catch this exception and give a more user friendly error message.