exception

[Peter Mathia]

Hi everyone,
is anybody able to tell me something about this error without posting my
code? I use javaFX 2.2 to develop Gantt chart visualizer. Sometimes I get
this exceptions when I want to update GUI in Platform.runLater thread.
The chart has Canvas as a background and every Task in chart is represented
by a Rectangle (drag/resize)...
Thank you!

Peter

java.lang.NullPointerException
    at com.sun.javafx.sg.prism.NGCanvas$RenderBuf.validate(NGCanvas.java:76)
    at com.sun.javafx.sg.prism.NGCanvas.initCanvas(NGCanvas.java:336)
    at com.sun.javafx.sg.prism.NGCanvas.renderContent(NGCanvas.java:316)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:187)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:39)
    at com.sun.javafx.sg.BaseNode.render(BaseNode.java:1145)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:204)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:420)
    at
com.sun.javafx.sg.prism.NGNode$CacheFilter.impl_renderNodeToScreen(NGNode.java:712)
    at com.sun.javafx.sg.BaseCacheFilter.render(BaseCacheFilter.java:168)
    at com.sun.javafx.sg.prism.NGNode$CacheFilter.render(NGNode.java:660)
    at com.sun.javafx.sg.prism.NGNode.renderCached(NGNode.java:487)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:183)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:39)
    at com.sun.javafx.sg.BaseNode.render(BaseNode.java:1145)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:204)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:420)
    at com.sun.javafx.sg.prism.NGNode.renderForClip(NGNode.java:429)
    at com.sun.javafx.sg.prism.NGNode.renderRectClip(NGNode.java:320)
    at com.sun.javafx.sg.prism.NGNode.renderClip(NGNode.java:346)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:179)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:39)
    at com.sun.javafx.sg.BaseNode.render(BaseNode.java:1145)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:204)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:420)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:187)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:39)
    at com.sun.javafx.sg.BaseNode.render(BaseNode.java:1145)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:204)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:187)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:39)
    at com.sun.javafx.sg.BaseNode.render(BaseNode.java:1145)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:204)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:420)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:187)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:39)
    at com.sun.javafx.sg.BaseNode.render(BaseNode.java:1145)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:204)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:420)
    at com.sun.javafx.sg.prism.NGNode.renderForClip(NGNode.java:429)
    at com.sun.javafx.sg.prism.NGNode.renderRectClip(NGNode.java:320)
    at com.sun.javafx.sg.prism.NGNode.renderClip(NGNode.java:346)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:179)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:39)
    at com.sun.javafx.sg.BaseNode.render(BaseNode.java:1145)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:204)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:420)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:187)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:39)
    at com.sun.javafx.sg.BaseNode.render(BaseNode.java:1145)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:204)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:187)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:39)
    at com.sun.javafx.sg.BaseNode.render(BaseNode.java:1145)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:204)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:420)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:187)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:39)
    at com.sun.javafx.sg.BaseNode.render(BaseNode.java:1145)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:204)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:420)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:187)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:39)
    at com.sun.javafx.sg.BaseNode.render(BaseNode.java:1145)
    at com.sun.javafx.tk.quantum.ViewPainter.doPaint(ViewPainter.java:117)
    at
com.sun.javafx.tk.quantum.AbstractPainter.paintImpl(AbstractPainter.java:175)
    at
com.sun.javafx.tk.quantum.PresentingPainter.run(PresentingPainter.java:73)
    at
java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at
java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:351)
    at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:178)
    at com.sun.prism.render.RenderJob.run(RenderJob.java:37)
    at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at
com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(QuantumRenderer.java:98)
    at java.lang.Thread.run(Thread.java:724)