Charts cannot be generated

[scorpp]

Adding charts to dashboard or viewing a Time Machine page is unable to render actual charts. Logs are full of stack traces

2015.08.06 23:27:55 ERROR web[o.s.s.c.ChartsServlet] Generating chart org.sonar.server.charts.deprecated.SparkLinesChart
java.lang.NullPointerException: null
    at sun.awt.FontConfiguration.getVersion(FontConfiguration.java:1264) ~[na:1.8.0_45-internal]
    at sun.awt.FontConfiguration.readFontConfigFile(FontConfiguration.java:219) ~[na:1.8.0_45-internal]
    at sun.awt.FontConfiguration.init(FontConfiguration.java:107) ~[na:1.8.0_45-internal]
    at sun.awt.X11FontManager.createFontConfiguration(X11FontManager.java:776) ~[na:1.8.0_45-internal]
    at sun.font.SunFontManager$2.run(SunFontManager.java:431) ~[na:1.8.0_45-internal]
    at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_45-internal]
    at sun.font.SunFontManager.<init>(SunFontManager.java:376) ~[na:1.8.0_45-internal]
    at sun.awt.X11FontManager.<init>(X11FontManager.java:57) ~[na:1.8.0_45-internal]
    at sun.reflect.GeneratedConstructorAccessor69.newInstance(Unknown Source) ~[na:na]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_45-internal]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:422) ~[na:1.8.0_45-internal]
    at java.lang.Class.newInstance(Class.java:442) ~[na:1.8.0_45-internal]
    at sun.font.FontManagerFactory$1.run(FontManagerFactory.java:83) ~[na:1.8.0_45-internal]
    at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_45-internal]
    at sun.font.FontManagerFactory.getInstance(FontManagerFactory.java:74) ~[na:1.8.0_45-internal]
    at java.awt.Font.getFont2D(Font.java:491) ~[na:1.8.0_45-internal]
    at java.awt.Font.defaultLineMetrics(Font.java:2176) ~[na:1.8.0_45-internal]
    at java.awt.Font.getLineMetrics(Font.java:2246) ~[na:1.8.0_45-internal]
    at org.jfree.chart.axis.NumberAxis.estimateMaximumTickLabelHeight(NumberAxis.java:974) ~[jfreechart-1.0.9.jar:na]
    at org.jfree.chart.axis.NumberAxis.selectVerticalAutoTickUnit(NumberAxis.java:1104) ~[jfreechart-1.0.9.jar:na]
    at org.jfree.chart.axis.NumberAxis.selectAutoTickUnit(NumberAxis.java:1048) ~[jfreechart-1.0.9.jar:na]
    at org.jfree.chart.axis.NumberAxis.refreshTicksVertical(NumberAxis.java:1249) ~[jfreechart-1.0.9.jar:na]
    at org.jfree.chart.axis.NumberAxis.refreshTicks(NumberAxis.java:1149) ~[jfreechart-1.0.9.jar:na]
    at org.jfree.chart.axis.NumberAxis.draw(NumberAxis.java:659) ~[jfreechart-1.0.9.jar:na]
    at org.jfree.chart.plot.XYPlot.drawAxes(XYPlot.java:3151) ~[jfreechart-1.0.9.jar:na]
    at org.jfree.chart.plot.XYPlot.draw(XYPlot.java:2666) ~[jfreechart-1.0.9.jar:na]
    at org.jfree.chart.JFreeChart.draw(JFreeChart.java:1222) ~[jfreechart-1.0.9.jar:na]
    at org.jfree.chart.JFreeChart.createBufferedImage(JFreeChart.java:1396) ~[jfreechart-1.0.9.jar:na]
    at org.sonar.server.charts.deprecated.BaseChart.getBufferedImage(BaseChart.java:114) ~[sonar-server-5.1.1.jar:na]
    at org.sonar.server.charts.deprecated.SparkLinesChart.getChartImage(SparkLinesChart.java:53) ~[sonar-server-5.1.1.jar:na]
    at org.sonar.server.charts.deprecated.BaseChart.exportChartAsPNG(BaseChart.java:120) ~[sonar-server-5.1.1.jar:na]
    at org.sonar.server.charts.ChartsServlet.deprecatedDoGet(ChartsServlet.java:152) [sonar-server-5.1.1.jar:na]
    at org.sonar.server.charts.ChartsServlet.doGet(ChartsServlet.java:56) [sonar-server-5.1.1.jar:na]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:618) [tomcat-embed-core-8.0.18.jar:8.0.18]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:725) [tomcat-embed-core-8.0.18.jar:8.0.18]
...

sonar image 5.1.1

[frommeyerc]

I have the same Issue.