I'm trying to add an Arcade Attribute Rule to an intermediate table / attributed relationship class between a table of Signs and a table of Sign Sites. It's an M:N many-to-many relationship. The Signs move around, so can be associated with many sites, and the intermediate table records the history of the signs movements, with to and from date fields, and a location field in addition to the Foreign Keys from both the Sign and Sign Site tables.
I'm trying to add an attribute rule to this intermediate table to auto-populate the 'Location' field, but I can't get a schema lock on the intermediate table. I can add rules to both the Sign and Sign Site tables without any problems, no lock issues, and the arcade is a piece that works on other tables.
I'm on ArcPro 2.4, working in a test Paas enterprise database. There are no other users in the system, just me, so how could I be getting a schema lock? And on only one table?
Has anyone ever seen this before?