It is a common misconception that you must use the Open resource file command before attempting to use a resource stored in the resource fork of your database structure (the .RSR file under Windows). As long as your resource ID's are unique in the Resource Files Chain there is no need to call Open resource file, because the database structure resource is opened automatically by 4D. The recommended range of resource ID's for your custom resources is 15,000..32,767. For more information see "The Resource Files Chain" in Command Resources.