I'll double check this to see if I can trust me. I was facing too many different problems on the same time today. So it's difficult to distinguish and to reproduce theme. If I'll face the same problem I'll provide the stacktrace. Seems that this happened to me when I was testing for the right expressions to be used for my arguments. Sometimes it seemed as if they weren't correct but regardless I could deploy the process and I earned the exception when starting process instances. Maybe another case where this exception is seen but the actual one is hard to find because it's in somewhere in the cause. "bwestrich" wrote : | Actually, I ran into one of these errors just now (java.lang.ClassCastException: org.jbpm.jpdl.internal.model.JpdlProcessDefinition cannot be cast to j | ava.util.List) and clearing the database didn't solve it. | | Digging a little deeper, it looks like (at least when a model is deployed in a JUnit environment) when the jBPM parser parses a model file, if there's an error (such as a java class is defined that can't be found, or a class cast exception), the exception is thrown to the console but parsing continues on. This leads to the above (hard to understand) error message occurring. If you look at your system console, you hopefully will see an exception just prior to the above one, which is more informative. | View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4263586#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...