Exception(explorer):unable to instantiate Java service tasks

[bluerain]

When trying to start the instance of the process from activiti explorer throws "Wrapped exception (with status template): couldn't instantiate class com.delegate.MyJavaDelegate"
I have added the jar files in tomcat/lib directory as it says in the userguide.

[frederikherema1]

When you are using the demo setup and you want to add your custom classes, you should add a jar containing your classes to the activiti-rest webapp lib. Don't forget to include the dependencies of your custom classes (if any) as wel. This is the same location where the activiti-engine jar is located. You can find this folder inside your distro at ${activiti.home}/apps/apache-tomcat-6.0.29/webapps/activiti-rest/lib/

You mean the ${activiti.home}/apps/apache-tomcat-6.0.29/webapps/activiti-rest/lib/ when you say "tomcat/lib" ?