It works only when the first record is selected. Ok, here is the deal. Open the sample app, go to Customer/Orders, type ROMEY and hit "Get Orders". Pick the third record for example, not the first one, go to Properties, put something in the Region field, press Save. Click Properties again, delete content of the Country field, press save ... voila. "Unable to save current data. See error icons for details", but ... there are no icons.