I have custom code “BeforeContactMove” that I added to the Pre Execute Steps of the Move Contact business rule in App Architect gets executed

When the user clicks the Move button on the contact Detail page, the "Move Contact" dialog opens and after entering the information, the OK button is clicked. At this time the "BeforeMoveContact" gets executed.

The BeforeMoveContact method checks if the contact being moved has any projects associated to it by calling another internal in-house Application. If there are projects associated to the contact, the custom method throws a Sage.Platform.Application.ValidationException with the following message as seen below. The message box is seen, but the OK button is missing. 

I am not sure as to why the OK button does not get rendered.

On the Contact Detail page, I do something similar. Whn a user clicks the delete button, custom code gets executed and a Sage.Platform.Application.ValidationException is thrown. The message and the OK button are rendered fine.