Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.animation.ValueAnimator.start()' on a null object reference
      at uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt$5.onAnimationUpdate(MaterialTapTargetPrompt.java:570)
      at android.animation.ValueAnimator.animateValue(ValueAnimator.java:1463)
      at android.animation.ValueAnimator.setCurrentFraction(ValueAnimator.java:642)
      at android.animation.ValueAnimator.setCurrentPlayTime(ValueAnimator.java:589)
      at android.animation.ValueAnimator.start(ValueAnimator.java:1106)
      at android.animation.ValueAnimator.start(ValueAnimator.java:1117)
      at uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt.startIdleAnimations(MaterialTapTargetPrompt.java:578)
      at uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt$4.onAnimationEnd(MaterialTapTargetPrompt.java:529)
      at android.animation.ValueAnimator.endAnimation(ValueAnimator.java:1239)
      at android.animation.ValueAnimator$AnimationHandler.doAnimationFrame(ValueAnimator.java:766)
      at android.animation.ValueAnimator$AnimationHandler$1.run(ValueAnimator.java:801)
      at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
      at android.view.Choreographer.doCallbacks(Choreographer.java:670)
      at android.view.Choreographer.doFrame(Choreographer.java:603)
      at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
      at android.os.Handler.handleCallback(Handler.java:739)
      at android.os.Handler.dispatchMessage(Handler.java:95)
      at android.os.Looper.loop(Looper.java:148)
      at android.app.ActivityThread.main(ActivityThread.java:5551)
      at java.lang.reflect.Method.invoke(Method.java)
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:734)
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:624)

Fatal Exception: java.lang.NullPointerException
Attempt to invoke virtual method 'void android.animation.ValueAnimator.start()' on a null object reference
uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt$5.onAnimationUpdate (MaterialTapTargetPrompt.java:570)
android.animation.ValueAnimator.animateValue (ValueAnimator.java:1463)
android.animation.ValueAnimator.setCurrentFraction (ValueAnimator.java:642)
android.animation.ValueAnimator.setCurrentPlayTime (ValueAnimator.java:589)
android.animation.ValueAnimator.start (ValueAnimator.java:1106)
android.animation.ValueAnimator.start (ValueAnimator.java:1117)
uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt.startIdleAnimations (MaterialTapTargetPrompt.java:578)
uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt$4.onAnimationEnd (MaterialTapTargetPrompt.java:529)
android.animation.ValueAnimator.endAnimation (ValueAnimator.java:1239)
android.animation.ValueAnimator$AnimationHandler.doAnimationFrame (ValueAnimator.java:766)
android.animation.ValueAnimator$AnimationHandler$1.run (ValueAnimator.java:801)
android.view.Choreographer$CallbackRecord.run (Choreographer.java:894)
android.view.Choreographer.doCallbacks (Choreographer.java:696)
android.view.Choreographer.doFrame (Choreographer.java:628)
android.view.Choreographer$FrameDisplayEventReceiver.run (Choreographer.java:880)
android.os.Handler.handleCallback (Handler.java:815)
android.os.Handler.dispatchMessage (Handler.java:104)
android.os.Looper.loop (Looper.java:207)
android.app.ActivityThread.main (ActivityThread.java:5692)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:905)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:766)