NullPointerException occur

[Kim-DongGeun]

I don't know when the exception is thrown
here is crash log
plz check it

Fatal Exception: java.lang.NullPointerException: Attempt to write to field 'int iamutkarshtiwari.github.io.ananas.editimage.EditImageActivity.i' on a null object reference

at iamutkarshtiwari.github.io.ananas.editimage.fragment.crop.CropFragment.onShow(CropFragment.java:145)
at iamutkarshtiwari.github.io.ananas.editimage.fragment.MainMenuFragment.onCropClick(MainMenuFragment.java:189)
at iamutkarshtiwari.github.io.ananas.editimage.fragment.MainMenuFragment.onClick(MainMenuFragment.java:161)
at android.view.View.performClick(View.java:7862)
at android.view.View.performClickInternal(View.java:7831)
at android.view.View.access$3600(View.java:879)
at android.view.View$PerformClick.run(View.java:29359)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:237)
at android.app.ActivityThread.main(ActivityThread.java:8167)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1100)