MPAndroidChart LineChart crash

FATAL EXCEPTION: main Process: PID: 9915 java.lang.NullPointerException: Attempt to invoke virtual method 'float com.github.mikephil.charting.data.Entry.getX()' on a null object reference at com.github.mikephil.charting.renderer.LineChartRenderer.drawCubicBezier(LineChartRenderer.java:236) at enter code herecom.github.mikephil.charting.renderer.LineChartRenderer.drawDataSet(LineChartRenderer.java:123) at com.github.mikephil.charting.renderer.LineChartRenderer.drawData(LineChartRenderer.java:101) at com.github.mikephil.charting.charts.BarLineChartBase.onDraw(BarLineChartBase.java:237)