Hi , We are generating the PDF using Vietnam Font in a Vietnamese application developed in java JARS Used: jasperreports-5.0.1.jar itextpdf-5.1.0.jar, com.lowagie.text_2.1.7.v201004222200.jar .otf Vietnamese Fonts loaded from external files jrxml files are located outside folders. The PDF generation fails some times without throwing any Exception message and this is not reproducible error. This error is coming randomly and once this error is occurred then the Server restart is required to generate the PDF. After the restart we are able to generate the PDF. Please see below the Error file log SystemErr R java.lang.NullPointerException SystemErr R at com.lowagie.text.pdf.CFFFontSubset.BuildNewLGSubrs(Unknown Source) SystemErr R at com.lowagie.text.pdf.CFFFontSubset.Process(Unknown Source) SystemErr R at com.lowagie.text.pdf.TrueTypeFontUnicode.writeFont(Unknown Source) SystemErr R at com.lowagie.text.pdf.FontDetails.writeFont(Unknown Source) SystemErr R at com.lowagie.text.pdf.PdfWriter.addSharedObjectsToBody(Unknown Source) SystemErr R at com.lowagie.text.pdf.PdfWriter.close(Unknown Source) SystemErr R at com.lowagie.text.pdf.PdfDocument.close(Unknown Source) SystemErr R at com.lowagie.text.Document.close(Unknown Source) SystemErr R at net.sf.jasperreports.engine.export.JRPdfExporter.exportReportToStream(JRPdfExporter.java:707) SystemErr R at net.sf.jasperreports.engine.export.JRPdfExporter.exportReport(JRPdfExporter.java:396) Any solution or pointer to resolve this issue will be highly appreciated