If you start Tomcat 7 and got the error:
java.lang.UnsupportedOperationException: This parser does not support specification "null" version "null"
Just put the parameter below and restart Tomcat:
-Djavax.xml.parsers.SAXParserFactory=com.sun.org.apache.xerces.internal.jaxp.SAXParserFactoryImpl
This happens because you have two parsers in your classpath, and the Tomcat is getting a error loading the wrong version.
