Why is a blank popup appearing on nougat and not previous versions ?

[AC Question]

Hello,
I have an app which is targetting SDK 21. When I try to run the app on nougat I get a blank dialog with an ok button. Do not know why the blank popup appears. It does not happen on marshmallow.

Thanks,
Raghu

 

[the tall guy]

Hi, what is targetting SDK21 mean? what is the app? what device do you have?