For some reason you are creating the user again. It seems that you are inserting again an user that already exist.
Can you enable the hibernate logs?
ok, I know why, in ContentData I put userId and that is used in process in ActorId, this user as String is: 'john1,john2,john3'
but I thought that way is good from manual jbpm, user1,user2,user3... with comma
reason was the lack of user in base, when I added john1,john2,john3 to base by add new User(john1)..., immediately began to work