java.lang.NoClassDefFoundError: Could not initialize class org.jfree.chart.axis.NumberAxis
        at org.jfree.chart.ChartFactory.createStackedXYAreaChart(ChartFactory.java:1613)
        at com.atlassian.bamboo.charts.timeperiod.SuccessRatioStackedAreaChart.getChart(SuccessRatioStackedAreaChart.java:66)
        at com.atlassian.bamboo.charts.CombinedBuildSummaryByTimeChart.generateChartParams(CombinedBuildSummaryByTimeChart.java:31)
        at com.atlassian.bamboo.ww2.actions.charts.ViewCombinedByTimePeriodChart.getCombinedByTimeChart(ViewCombinedByTimePeriodChart.java:147)
        at sun.reflect.GeneratedMethodAccessor1234.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:517)
        at ognl.OgnlRuntime.getMethodValue(OgnlRuntime.java:931)
        at ognl.ObjectPropertyAccessor.getPossibleProperty(ObjectPropertyAccessor.java:53)
        at ognl.ObjectPropertyAccessor.getProperty(ObjectPropertyAccessor.java:121)
        at com.opensymphony.xwork.util.OgnlValueStack$ObjectAccessor.g