Crashing on devices below SDK Version 19

[Sarun1001]

Hi, first of all thanks for this awesome lib. Lib tend to crash on almost all emulators and devices below SDK 19. But working fine on latest devices. Any idea ?... Complete stacktrace...

E/AndroidRuntime: FATAL EXCEPTION: main java.lang.NullPointerException at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:465) at android.view.View.measure(View.java:15172) at it.beppi.balloonpopuplibrary.BalloonPopup.draw(BalloonPopup.java:255) at it.beppi.balloonpopuplibrary.BalloonPopup.show(BalloonPopup.java:213) at it.beppi.balloonpopuplibrary.BalloonPopup.access$400(BalloonPopup.java:35) at it.beppi.balloonpopuplibrary.BalloonPopup$Builder.show(BalloonPopup.java:541) at it.beppi.knoblibrary.Knob.displayBalloons(Knob.java:273) at it.beppi.knoblibrary.Knob.onDraw(Knob.java:133) at android.view.View.draw(View.java:13458) at android.view.View.getDisplayList(View.java:12409) at android.view.View.getDisplayList(View.java:12453) at android.view.View.draw(View.java:13182) at android.view.ViewGroup.drawChild(ViewGroup.java:2929) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799) at android.view.View.getDisplayList(View.java:12407) at android.view.View.getDisplayList(View.java:12453) at android.view.View.draw(View.java:13182) at android.view.ViewGroup.drawChild(ViewGroup.java:2929) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799) at android.view.View.getDisplayList(View.java:12407) at android.view.View.getDisplayList(View.java:12453) at android.view.View.draw(View.java:13182) at android.view.ViewGroup.drawChild(ViewGroup.java:2929) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799) at android.view.View.getDisplayList(View.java:12407) at android.view.View.getDisplayList(View.java:12453) at android.view.View.draw(View.java:13182) at android.view.ViewGroup.drawChild(ViewGroup.java:2929) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799) at android.view.View.draw(View.java:13461) at android.view.View.getDisplayList(View.java:12409) at android.view.View.getDisplayList(View.java:12453) at android.view.View.draw(View.java:13182) at android.view.ViewGroup.drawChild(ViewGroup.java:2929) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799) at android.view.View.getDisplayList(View.java:12407) at android.view.View.getDisplayList(View.java:12453) at android.view.View.draw(View.java:13182) at android.view.ViewGroup.drawChild(ViewGroup.java:2929) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799) at android.view.View.getDisplayList(View.java:12407) at android.view.View.getDisplayList(View.java:12453) at android.view.View.draw(View.java:13182) at android.view.ViewGroup.drawChild(ViewGroup.java:2929) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799) at android.view.View.draw(View.java:13461) at android.widget.FrameLayout.draw(FrameLayout.java:467) at android.view.View.getDisplayList(View.java:12409) at android.view.View.getDisplayList(View.java:12453) at android.view.View.draw(View.java:13182) at android.view.ViewGroup.drawChild(ViewGroup.java:2929) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799) at android.view.View.getDisplayList(View.java:12407) at android.view.View.getDisplayList(View.java:12453) at android.view.View.draw(View.java:13182) at android.view.ViewGroup.drawChild(ViewGroup.java:2929) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799) at android.view.View.getDisplayList(View.java:12407) at android.view.View.getDisplayList(View.java:12453) at android.view.View.draw(View.java:13182) at android.view.ViewGroup.drawChild(ViewGroup.java:2929) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799) at android.view.View.getDisplayList(View.java:12407) at android.view.View.getDisplayList(View.java:12453) at android.view.View.draw(View.java:13182) at android.view.ViewGroup.drawChild(ViewGroup.java:2929) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2799) at android.view.View.draw(View.java:13461) at android.widget.FrameLayout.draw(FrameLayout.java:467) at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:2183) at android.view.View.getDisplayList(View.java:12409) at android.view.View.getDisplayList(View.java:12453)