Detailed information:

    Error number 11015 in 11: Exception while exporting
com.xpn.xwiki.XWikiException: Error number 11015 in 11: Exception while exporting
	at com.xpn.xwiki.web.ExportAction.render(ExportAction.java:82)
	at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:347)
	at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:148)
	at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:425)
	at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:228)
	at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
	at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:115)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.xwiki.wysiwyg.server.filter.ConversionFilter.doFilter(ConversionFilter.java:126)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at com.xpn.xwiki.plugin.webdav.XWikiDavFilter.doFilter(XWikiDavFilter.java:66)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.xwiki.container.servlet.filters.internal.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:208)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.xwiki.container.servlet.filters.internal.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:111)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1074)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:745)
Caused by: com.xpn.xwiki.XWikiException: Error number 12002 in 12: Exception while exporting rtf
	at com.xpn.xwiki.pdf.impl.PdfExportImpl.createException(PdfExportImpl.java:569)
	at com.xpn.xwiki.pdf.impl.PdfExportImpl.renderXSLFO(PdfExportImpl.java:343)
	at com.xpn.xwiki.pdf.impl.PdfExportImpl.exportXHTML(PdfExportImpl.java:271)
	at com.xpn.xwiki.pdf.impl.PdfExportImpl.exportHtml(PdfExportImpl.java:224)
	at com.xpn.xwiki.pdf.impl.PdfExportImpl.export(PdfExportImpl.java:210)
	at com.xpn.xwiki.web.ExportAction.export(ExportAction.java:223)
	at com.xpn.xwiki.web.ExportAction.render(ExportAction.java:79)
	... 42 more
Caused by: javax.xml.transform.TransformerException: org.apache.fop.fo.ValidationException: "fo:list-block" is missing child elements. Required content model: marker* (list-item)+ (See position 27:73)
	at org.apache.xalan.transformer.TransformerIdentityImpl.transform(TransformerIdentityImpl.java:502)
	at com.xpn.xwiki.pdf.impl.PdfExportImpl.renderXSLFO(PdfExportImpl.java:327)
	... 47 more
Caused by: org.apache.fop.fo.ValidationException: "fo:list-block" is missing child elements. Required content model: marker* (list-item)+ (See position 27:73)
	at org.apache.fop.events.ValidationExceptionFactory.createException(ValidationExceptionFactory.java:38)
	at org.apache.fop.events.EventExceptionManager.throwException(EventExceptionManager.java:54)
	at org.apache.fop.events.DefaultEventBroadcaster$1.invoke(DefaultEventBroadcaster.java:175)
	at com.sun.proxy.$Proxy67.missingChildElement(Unknown Source)
	at org.apache.fop.fo.FONode.missingChildElementError(FONode.java:549)
	at org.apache.fop.fo.flow.ListBlock.endOfNode(ListBlock.java:102)
	at org.apache.fop.fo.FOTreeBuilder$MainFOHandler.endElement(FOTreeBuilder.java:349)
	at org.apache.fop.fo.FOTreeBuilder.endElement(FOTreeBuilder.java:177)
	at org.apache.xalan.transformer.TransformerIdentityImpl.endElement(TransformerIdentityImpl.java:1102)
	at org.apache.xerces.parsers.AbstractSAXParser.endElement(Unknown Source)
	at org.apache.xerces.parsers.AbstractXMLDocumentParser.emptyElement(Unknown Source)
	at org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
	at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
	at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
	at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
	at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
	at org.apache.xalan.transformer.TransformerIdentityImpl.transform(TransformerIdentityImpl.java:485)
	... 48 more