应用程序在启动时以双窗格模式崩溃

Actually iam making an app which displays popular movies ( popular movie app project of udacity course) and i have two activites main activity and detail activity but when i tried to make my app run on a tablet it crashes and can't display even the main activity on launching the app and i dont know what is missing .... Also , i want to know how can i specify that my app should run on different screen sizes for tablets..Actually iam making an app which displays popul