Hello Gordon. Many thanks for your reply. I have checked the FAQs as you suggest and have done an "environment check" to establish the versions that are being used on the server. It would appear that I am accessing the new Xalan version correctly. I would prefer to use Xerces 2.4 however as this is the version that was tested with Xalan 2.5. I will have to ask my webhoster to change this.
#---- BEGIN writeEnvironmentReport($Revision: 1.17 $): Useful stuff found: ---- java.version=1.4.1_01 version.xalan2x=Xalan Java 2.5.D1 version.JAXP=1.1 version.SAX=2.0 version.crimson=present-unknown-version java.class.path=WARNING: SecurityException thrown accessing system classpath properties version.ant=not-present sun.boot.class.path=/home/tomcat41/common/endorsed/xercesImpl.jar:/home/tomcat41/common/endorsed/xmlParserAPIs.jar:/home/tomcat41/common/endorsed/xalan.jar:/opt/j2sdk1.4.1_01/jre/lib/rt.jar:/opt/j2sdk1.4.1_01/jre/lib/i18n.jar:/opt/j2sdk1.4.1_01/jre/lib/sunrsasign.jar:/opt/j2sdk1.4.1_01/jre/lib/jsse.jar:/opt/j2sdk1.4.1_01/jre/lib/jce.jar:/opt/j2sdk1.4.1_01/jre/lib/charsets.jar:/opt/j2sdk1.4.1_01/jre/classes version.DOM.draftlevel=2.0fd version.DOM=2.0 version.xalan1=not-present version.xalan2_2=Xalan Java 2.5.D1 version.xerces2=Xerces-J 2.3.0 version.xerces1=not-present #----- END writeEnvironmentReport: Useful properties found: ----- # YAHOO! Your environment seems to be OK. My error is a "NoClassDefFound" error, yet does not tell me the class it cannot find. I am inclined to think it is more of an XML parsing error rather than a fault with the Xalan setup. I also think a difference in compiling on Win98 and running on Linux is a possible cause. java.lang.NoClassDefFoundError at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:140) at org.apache.xalan.serialize.SerializerFactory.getSerializer(SerializerFactory.java:125) Thank you, Andrew.