java.lang.IllegalStateException: Could not execute method for android:onClick
	at androidx.appcompat.app.i$a.onClick(Unknown Source:32)
	at android.view.View.performClick(View.java:7448)
	at android.view.View.performClickInternal(View.java:7421)
	at android.view.View.access$3700(View.java:838)
	at android.view.View$PerformClick.run(View.java:28870)
	at android.os.Handler.handleCallback(Handler.java:938)
	at android.os.Handler.dispatchMessage(Handler.java:99)
	at android.os.Looper.loopOnce(Looper.java:201)
	at android.os.Looper.loop(Looper.java:288)
	at android.app.ActivityThread.main(ActivityThread.java:7986)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:553)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
Caused by: java.lang.reflect.InvocationTargetException
	at java.lang.reflect.Method.invoke(Native Method)
	at androidx.appcompat.app.i$a.onClick(Unknown Source:23)
	... 12 more
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void h9.b.d()' on a null object reference
	at h9.a$e.a(Unknown Source:2)
	at h9.a.c(Unknown Source:8)
	at com.entitcs.office_attendance.camera.FaceTrackerActivity.groupAttendance(Unknown Source:2)
	... 14 more