1. open the http://www.emforge.org/wiki/NotCreatedWikiPage
2. click link "Get as PDF" - there is the error:

HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

java.lang.NullPointerException
        com.ecyrd.jspwiki.WikiEngine.getHTML(WikiEngine.java:1318)
        com.ecyrd.jspwiki.WikiEngine.getHTML(WikiEngine.java:1351)
        com.ecyrd.jspwiki.WikiEngine.getHTML(WikiEngine.java:1332)
        com.palbrattberg.jspwiki.Wiki2PDFServlet.doGet(Wiki2PDFServlet.java:186)
        ru.emdev.EmForge.wiki.web.PDFServlet.doGet(PDFServlet.java:43)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
        org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:323)
        org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:265)
        org.acegisecurity.intercept.web.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:107)
        org.acegisecurity.intercept.web.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:72)
        org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:275)
        org.acegisecurity.ui.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:124)
        org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:275)
        org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:125)
        org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:275)
        org.acegisecurity.ui.basicauth.BasicProcessingFilter.doFilter(BasicProcessingFilter.java:174)
        org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:275)
        org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:271)
        org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:275)
        org.acegisecurity.ui.logout.LogoutFilter.doFilter(LogoutFilter.java:110)
        org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:275)
        org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)
        org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:275)
        org.acegisecurity.util.FilterChainProxy.doFilter(FilterChainProxy.java:149)
        org.acegisecurity.util.FilterToBeanProxy.doFilter(FilterToBeanProxy.java:98)
        org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)
        org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:75)
        org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:63)
        org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:75)

note The full stack trace of the root cause is available in the Apache Tomcat/6.0.14 logs.
Apache Tomcat/6.0.14