"Invalid Reference Id" error when creating records in a child table
I have a page containing a "parent" model called "Workshop" and a table beneath it where users can create rows for "Workshop Attendance". When users click the green plus icon in the table, it fills in the parent record automatically in the lookup field (Excellent!). However, when I do so and save the page, it throws the error "Invalid Reference Id: Workshop" and no child records in the table are saved. What am I'm missing?