Vuforia failed to initialize

hey there,

I am developing an application where there are total two scene, my first scene works with AR camera i.e, vuforia. Here in the scene,  there are some triggers with takes user to next scene. This scene deals with normal camera and VR Camera , I have VR button option which switch between normal and VR mode.

This Works fine in the Unity Editor, but When I generate APK and run it. It gives me error of vuforia Failed to initialize. I researched, found only mixed reality answer. Since this is not a case of mixed reality, Can anyone help me on this?

I using Unity version 5.6.2f1, Vuforia version 6.2 and Cardboard version 0.6.