I'm trying to create several diagramas in several files and sometimes I receive this message "java.util.ConcurrentModificationException
       at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
       at java.util.AbstractList$ListItr.set(AbstractList.java:409)
       at java.util.Collections.sort(Collections.java:163)
       at com.mindfusion.pdf.PdfPage.Save(Unknown Source)
       at com.mindfusion.pdf.PdfDocument.Save(Unknown Source)
       at com.mindfusion.pdf.PdfGraphics2D.dispose(Unknown Source)
       at java.awt.Graphics.finalize(Graphics.java:1147)
       at com.mindfusion.pdf.PdfGraphics2D.finalize(Unknown Source)
       at java.lang.ref.Finalizer.invokeFinalizeMethod(Native Method)
       at java.lang.ref.Finalizer.runFinalizer(Finalizer.java:83)
       at java.lang.ref.Finalizer.access$100(Finalizer.java:14)
       at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:160)
java.util.ConcurrentModificationException
       at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
       at java.util.AbstractList$Itr.next(AbstractList.java:343)
       at java.util.Collections.sort(Collections.java:162)
       at com.mindfusion.pdf.PdfPage.Save(Unknown Source)
       at com.mindfusion.pdf.PdfDocument.Save(Unknown Source)
       at com.mindfusion.pdf.PdfGraphics2D.dispose(Unknown Source)
       at java.awt.Graphics.finalize(Graphics.java:1147)
       at com.mindfusion.pdf.PdfGraphics2D.finalize(Unknown Source)
       at java.lang.ref.Finalizer.invokeFinalizeMethod(Native Method)
       at java.lang.ref.Finalizer.runFinalizer(Finalizer.java:83)
       at java.lang.ref.Finalizer.access$100(Finalizer.java:14)
       at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:160)
"
Do you know why it is happening?
thanks...

I am using awt and pdf export, I need to create a diagram with 130 pages, but if I create one file with 130 pages the process takes a lot of time that's why I'm creating one diagram with one page. Sometimes I receive the error and one or two files are incomplete.

Thank you.

Ignacio.