I agree that it probably is a classloader problem, but I have no idea what to do about it. I tried what you said, and put the catalina-ant.jar in my CLASSPATH variable ( I am running windows 7 64 bit ), but I got the same error. I also tried removing catalina-ant from tomcat's lib folder, but more of the same.
Any more suggestions/ideas would be much appreciated.
I don't know if this will be helpful or not, but my TOMCAT_HOME/lib folder looks like this:
annotations-api.jar
catalina-ant.jar
catalina-ha.jar
catalina-tribes.jar
catalina.jar
ecj-3.6.jar
el-api.jar
jasper-el.jar
jasper.jar
jsp-api.jar
servlet-api.jar
tomcat-api.jar
tomcat-coyote.jar
tomcat-dbcp.jar
tomcat-i18n-es.jar
tomcat-i18n-fr.jar
tomcat-i18n-ja.jar
tomcat-util.jar
And my ANT_HOME/lib directory looks like so:
ant-antlr.jar
ant-antlr.pom
ant-apache-bcel.jar
ant-apache-bcel.pom
ant-apache-bsf.jar
ant-apache-bsf.pom
ant-apache-log4j.jar
ant-apache-log4j.pom
ant-apache-oro.jar
ant-apache-oro.pom
ant-apache-regexp.jar
ant-apache-regexp.pom
ant-apache-resolver.jar
ant-apache-resolver.pom
ant-apache-xalan2.jar
ant-apache-xalan2.pom
ant-commons-logging.jar
ant-commons-logging.pom
ant-commons-net.jar
ant-commons-net.pom
ant-jai.jar
ant-jai.pom
ant-javamail.jar
ant-javamail.pom
ant-jdepend.jar
ant-jdepend.pom
ant-jmf.jar
ant-jmf.pom
ant-jsch.jar
ant-jsch.pom
ant-junit.jar
ant-junit.pom
ant-junit4.jar
ant-junit4.pom
ant-launcher.jar
ant-launcher.pom
ant-netrexx.jar
ant-netrexx.pom
ant-parent.pom
ant-swing.jar
ant-swing.pom
ant-testutil.jar
ant-testutil.pom
ant.jar
ant.pom
libraries.properties
I don't know if there might be two instances of the InstallTask class or something?