Community Relation hdl - Relation Number error

Hello,

I need to create an HDL to load courses into a community.
The HDL I have prepared is the following:

The issue I’m facing is with the RelationNumber, which keeps throwing an error.
I’ve tried several combinations, including using CourseNumber_CommunityNumber, but I still get the same error. As you can see, I’m not even prefixing it with “OLC”.

Has anyone encountered this before or can suggest the correct format for the RelationNumber?

Thank you,

Rebecca