Download c3p0-0.9.1.jar and put it in <TOMCAT_HOME>\webapps\jbpm\WEB-INF\lib folder Issue will be resolved. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4028736#4028736 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4028736