When joining files using a derived field, you may encounter the error - 'File xxx is not referenced in the JOIN specification'. You can avoid this error by making a small change to your design preferences.
- Press the OK button to close the error message.
- From the menu, select Options\ViewPoint Options\Design Tab.
- Un-check both Ensure files are joined and Enable auto joining in the File Join Options section.
This will allow the view to run with the derived join.