Adding reference fields to multi-reference or sub table error

Wappler Version : 7.0.0 beta 14
Operating System: Windows 11
Server Model: Node
Database Type: Postgres

Expected behavior

Adding reference fields to multi-reference or sub tables should work

Actual behavior

A warning icon is shown on the field and attempting to apply the change gives a validation error.

hovering over the error icon also does not display the error statement or give any indication for the cause of the error.

If I open Wappler 6, then I can apply the same change without encountering the error, so something has changed between the versions.