app crashes on changing the display mode

I am using iPhone6(iOS 8.4.1) to test the app. When I open the app to play a video and then change the display from standard to zoom and again go to app it crashes.

Here is some part of the log file :

Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 libsystem_kernel.dylib 0x0000000195c0f270 __pthread_kill + 8
1 libsystem_pthread.dylib 0x0000000195cad15c pthread_kill + 108
2 libsystem_c.dylib 0x0000000195b86a9c abort + 108
3 GraphicsServices 0x000000018d0b32e8 _GSRegisterPurpleNamedPortInPrivateNamespace + 420
4 GraphicsServices 0x000000018d0b21d0 _GSEventInitializeApp + 136
5 UIKit 0x000000018825aa88 UIApplicationMain + 708

Thank you