Copy item workflow Action workflow suspended getting error 

400: BadRequest: The user does not exist or is not unique. (Correlation Id: c91465c2-0afd-433e-a0ac-d7595e5c4246). WorkflowInstanceId : 14271b68-0230-4633-b6a1-bd517f238969

list having 6 People and group fields all the user in the item active user only