Thanks for your answer, Maksim!
This is the technical error popup:
At this moment I don't have access to the system, so I need to check the base component, but the scfld does not seem familiar. The app was created with a master detail CRUD template with Web IDE.
An interesting detail also is that when I update the entity (with oModel.submitChanges()), and the service raises the same exception, the same technical popup does NOT appear. I think there might be some issue with my Odata model and/or the way it gets called.
Kind regards,
Karri