thanks for your answer, I now know how to handle this via the instance.
But coming back to my real application with the Oracle DB another problem raised that I really don not understand.
I defines 3 tables, one in the middle (PRO) and two related tables (HST and PRT), both defined in the same way.
I then wanted to define a new view on entity PRO with the relations to the others, see below:
running the application WITHOUT having defined a UI I get the unexpected error:
just removing the HST relation in the view (see below) then the application runs without error:
This is very curious and I don’t have any idea how to solve the problem…