So I was following the steps as mentioned by Bucky in his tutorial #11 and accordingly I created a project with no activity but when I tried to add a blank activity from left panel of Android Studio, while following his steps all along, it showed problem in rendering in the 'design' tab of main_activity.xml

How can I resolve this problem?

Edit - For some reason the problem resolves itself if I change the theme into any from AppTheme to any of the remaining ones but if I revert back to AppTheme same problem arises again (o_O)