Caused by: java.lang.NullPointerException at sun.lwawt.macosx.LWCToolkit.getScreenResolution(LWCToolkit.java:343)

[jayhawk]

I got this error when I try to render PDF when my server screen is off. I'm using OSX Lion with Java 1.7.0_05

Oops: CConvertException
An unexpected error occured caused by exception CConvertException: ERROR: An unhandled exception occured: null

play.exceptions.UnexpectedException: Unexpected Error
    at play.modules.pdf.RenderPDFTemplate.writePDF(RenderPDFTemplate.java:151)
    at play.modules.pdf.PDF.renderTemplateAsPDF(PDF.java:239)
    at play.modules.pdf.PDF.writePDF(PDF.java:190)
    at controllers.comms.Mails.confirmAppointment(Mails.java:91)
    at models.calendar.CalendarServer.schedule(CalendarServer.java:268)
    at controllers.NewAppointment.doSchedule(NewAppointment.java:509)
    at controllers.NewAppointment.newAppointment(NewAppointment.java:198)
    at play.mvc.ActionInvoker.invokeWithContinuation(ActionInvoker.java:557)
    at play.mvc.ActionInvoker.invoke(ActionInvoker.java:508)
    at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:484)
    at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:479)
    at play.mvc.ActionInvoker.invoke(ActionInvoker.java:161)
    at Invocation.HTTP Request(Play!)
Caused by: org.allcolor.yahp.converter.IHtmlToPdfTransformer$CConvertException: ERROR: An unhandled exception occured: null
    at org.allcolor.yahp.cl.converter.CHtmlToPdfFlyingSaucerTransformer.transform(CHtmlToPdfFlyingSaucerTransformer.java:809)
    at play.modules.pdf.RenderPDFTemplate.renderDoc(RenderPDFTemplate.java:142)
    at play.modules.pdf.RenderPDFTemplate.renderPDF(RenderPDFTemplate.java:118)
    at play.modules.pdf.RenderPDFTemplate.writePDF(RenderPDFTemplate.java:149)
    ... 12 more
Caused by: java.lang.NullPointerException
    at sun.lwawt.macosx.LWCToolkit.getScreenResolution(LWCToolkit.java:343)
    at org.xhtmlrenderer.layout.SharedContext.<init>(SharedContext.java:109)
    at org.xhtmlrenderer.pdf.ITextRenderer.<init>(ITextRenderer.java:79)
    at org.xhtmlrenderer.pdf.ITextRenderer.<init>(ITextRenderer.java:70)
    at org.allcolor.yahp.cl.converter.CHtmlToPdfFlyingSaucerTransformer$_ITextRenderer.<init>(CHtmlToPdfFlyingSaucerTransformer.java:89)
    at org.allcolor.yahp.cl.converter.CHtmlToPdfFlyingSaucerTransformer.getITextRenderer(CHtmlToPdfFlyingSaucerTransformer.java:453)
    at org.allcolor.yahp.cl.converter.CHtmlToPdfFlyingSaucerTransformer.transform(CHtmlToPdfFlyingSaucerTransformer.java:582)
    ... 15 more