The problem happens because there is a call to AddToActivity in DesignerCreateView that is done with CallSubDelayed. It must use CallSubDelayed because it is not possible to load a layout file while a file is being loaded.
The solution is to use CallSubDelayed in your code:
Code:
Sub Activity_Create(FirstTime As Boolean)
Activity.LoadLayout("1")
CallSubDelayed(Me, "SetDate")
End Sub
Sub SetDate
ADP.SetDate(DateTime.Now, True)
End Sub