I have attached the error which I received on the console while running my jBPM project. Also I am attaching my code and persistence.xml. I am not able to solve this issue for long time. Please help me in this.
you need to make sure that you rask server is capable of getting information about users, for instance you can register user group callback like this:
where userGroupCallback is instance of implementation of UserGroupCallback interface for example DefaultUserGroupCallbackImpl