Vibration null pointer exception

[EhsanMashhadi]

I have got an exception from Firebase:

Fatal Exception: java.lang.NullPointerException
Attempt to read from field 'android.os.VibrationEffect com.android.server.VibratorService$Vibration.mEffect' on a null object reference

android.view.View.performHapticFeedback (View.java:23916)
com.andrognito.patternlockview.PatternLockView.detectAndAddHit (PatternLockView.java:814)
com.andrognito.patternlockview.PatternLockView.handleActionMove (PatternLockView.java:979)
com.andrognito.patternlockview.PatternLockView.onTouchEvent (PatternLockView.java:448)
android.view.View.dispatchTouchEvent (View.java:12629)
android.app.Activity.dispatchTouchEvent (Activity.java:3441)