There are lots of limitations when you run in Updateable mode, e.g. you can’t have any expressions or joins. The old editor first tried to run in Updateable mode, and if unsuccessful, just ran the unchanged query. So you should see the message ‘not Updateable’ in the status pane. I guess, UE should do the same thing or similar. At least, the message should be more clear. The good thing, in my opinion, is that UE doesn’t ‘remember’ Updateable mode, so you must explicitly switch it on if you want to edit data. And you wouldn’t expect to succeed when trying to update ‘dual’, or a query with expressions, would you?