While tinkering with the relationship properties in my Core Data model, my app suddenly failed to compile with this error:
error: Unsupported Feature: to-many relationship [Entity].[attribute]
option requires Mac OS X 10.7 or later
While it says to-many relationship is not supported, I know that’s not the real problem as I have been compiling fine with the ‘to-many‘ option turned on for a few weeks. What it’s really trying to tell you is an ‘ordered‘ AND ‘to-many‘ relationship is not supported. Once I unchecked the ‘ordered‘ option the app build fine again.