Problem with extension::qt::qtAssociation2ColumnWidget with associations whose NumberOfRequires > 0

Assume you have an association rule that requires at least 1 thing to be associated with the attribute. If you associated n things to the attribute and then disassociate the 1st thing, the widget will indicate that the associations are invalid.

This is due to the fact that the underlying ReferenceItem's first entry is now unset and therefore invalid.