phantomjs and pdf rendering

I have followed the link to turn on phantomjs for pdf rendering:  http://community.jaspersoft.com/wiki/phantomjs-libary-jasperreports-serve

Am currently recieving this error

2016-03-10 08:39:40,729 ERROR AsyncThumbnailCreatorImpl,pool-14-thread-1:59 - net.sf.jasperreports.engine.JRRuntimeException: java.lang.NullPointerException
net.sf.jasperreports.engine.JRRuntimeException: java.lang.NullPointerException
    at com.jaspersoft.jasperreports.highcharts.charts.ChartGraphics2DHandler.exportElement(ChartGraphics2DHandler.java:52)
    at net.sf.jasperreports.engine.export.draw.FrameDrawer.draw(FrameDrawer.java:247)
    at net.sf.jasperreports.engine.export.draw.FrameDrawer.draw(FrameDrawer.java:199)
    at net.sf.jasperreports.engine.export.JRGraphics2DExporter.exportPage(JRGraphics2DExporter.java:343)
    at net.sf.jasperreports.engine.export.JRGraphics2DExporter.exportReportToGraphics2D(JRGraphics2DExporter.java:312)
    at net.sf.jasperreports.engine.export.JRGraphics2DExporter.exportReport(JRGraphics2DExporter.java:237)
    at net.sf.jasperreports.engine.print.JRPrinterAWT.printPageToImage(JRPrinterAWT.java:285)
    at net.sf.jasperreports.engine.JasperPrintManager.printToImage(JasperPrintManager.java:286)
    at com.jaspersoft.jasperserver.api.metadata.common.service.impl.ThumbnailGenerationServiceImpl.obtainImage(ThumbnailGenerationServiceImpl.java:71)
    at com.jaspersoft.jasperserver.api.metadata.common.service.impl.ThumbnailGenerationServiceImpl.createThumbnail(ThumbnailGenerationServiceImpl.java:50)
    at com.jaspersoft.jasperserver.api.metadata.common.service.impl.ThumbnailGenerationServiceImpl.createThumbnail(ThumbnailGenerationServiceImpl.java:24)
    at com.jaspersoft.jasperserver.api.metadata.common.service.impl.AsyncThumbnailCreatorImpl$ThumbnailRunnable.run(AsyncThumbnailCreatorImpl.java:55)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:724)
Caused by: java.lang.NullPointerException
    at java.io.ByteArrayInputStream.<init>(ByteArrayInputStream.java:106)
    at net.sf.jasperreports.renderers.BatikRenderer.ensureSvg(BatikRenderer.java:215)
    at net.sf.jasperreports.renderers.BatikRenderer.ensureSvg(BatikRenderer.java:237)
    at net.sf.jasperreports.renderers.BatikRenderer.getDimension(BatikRenderer.java:155)
    at net.sf.jasperreports.engine.export.draw.ImageDrawer.draw(ImageDrawer.java:130)
    at com.jaspersoft.jasperreports.highcharts.charts.ChartGraphics2DHandler.exportElement(ChartGraphics2DHandler.java:50)
    ... 17 more
 

I'm looking for clues as to how to fix this.  Please answer if you know the following questions:

- Is there anymore specific errors besides this?

- is there a way to generate pdf's from commandline?  Maybe with ant?  So I can see the errors first hand?

- has anyone else had trouble turning on phantomjs for rendering pdf rendering purposes?

-- Why would I want to use phantomjs?  t's related to my previous question that never got answered (http://community.jaspersoft.com/questions/957896/pdf-renderrjs-timing-out)