[xwiki-users] Export to PDF java.lang.NullPointerException on some pages (possibly if images are too big)

When trying to export PDF some (not all) page of my XWiki 7.2, I get an error in the log and the PDF is never generated. HTML export works fine. Here are the first lines from the error : Dec 2 09:37:07 xwiki01 server: java.lang.NullPointerException: Parameter alpha must not be null Dec 2 09:37:07 xwiki01 server: at org.apache.fop.pdf.AlphaRasterImage.<init>(AlphaRasterImage.java:57) ~[fop-1.1.jar:na] Dec 2 09:37:07 xwiki01 server: at org.apache.fop.pdf.AlphaRasterImage.<init>(AlphaRasterImage.java:71) ~[fop-1.1.jar:na] Dec 2 09:37:07 xwiki01 server: at org.apache.fop.render.pdf.ImageRenderedAdapter.setup(ImageRenderedAdapter.java:127) ~[fop-1.1.jar:na] Dec 2 09:37:07 xwiki01 server: at org.apache.fop.pdf.PDFDocument.addImage(PDFDocument.java:816) ~[fop-1.1.jar:na] Dec 2 09:37:07 xwiki01 server: at org.apache.fop.render.pdf.AbstractPDFImageHandler.handleImage(AbstractPDFImageHandler.java:46) ~[fop-1.1.jar:na] I can't say for sure that the size of the images in those pages is the cause of the export failure, but just before the stacktrace, I get a few WARN Dec 2 09:37:06 xwiki01 server: 2015-12-02 09:37:06,773 [ http://xwiki01:8080/xwiki/bin/export/White_Rabbit/Fabrication/GitLab+-+Manu… ] WARN o.a.f.a.FOUserAgent - Line 1 of a paragraph overflows the available area by 9000 millipoints. (See position 26:14146) Dec 2 09:37:07 xwiki01 server: 2015-12-02 09:37:07,104 [ http://xwiki01:8080/xwiki/bin/export/White_Rabbit/Fabrication/GitLab+-+Manu… ] ERROR o.a.f.a.FOUserAgent - Error while rendering page 3. Reason: java.lang.NullPointerException: Parameter alpha must not be null Dec 2 09:37:07 xwiki01 server: java.lang.NullPointerException: Parameter alpha must not be null Have you already seen this problem? I think I've found similar issues but for version 4.X back in 2012, though it was about "bad" PNG images then. Regards, Denis GERMAIN