Hi Andie,
Then why are you going to implement it again? The popup is popping up because its implemented somewhere, you have to find it and remove it.
I forgot to metion an important thing, The method name need not be on_before_wa_change always, It can have any name. You have to search for Event Handler methods in your Window or View Class and check if it is Assigned to the event before_workarea_content_change.
thats the method you should delete, I hope you know how to check if the method is an event handler or not and the event related to a method.
Regards,
Pratheek