Join on Derived Fields

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. 

1. Press the OK button to close the error message.
    
2. From the menu, select Options\ViewPoint Options\Design Tab.
    
3. 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.