I would probably recommend logging that with support for a thorough look, but at a glance it sounds like when you are saving it is attempting to populate a Customer field with a Support Group value (probably as this is the Analysts Primary Group) which is obviously causing a conflict because, although both are Groups they are different Group Types (Customer and Support Group).
Try adding a Customer and Support Group to this Analyst, then ensure the Primary Group is set to the Customer group not the Support Group and see if you get the same error. If you do, then definitely log this with support. If you don't, still log it with support but at least you'll have more of an idea where the problem lies.
You are experiencing a common problem that occurs when you have not set uup the users and groups correctly in the system. Before I answer anymore on this, please have a read of the following community article and especially my response outlining the rules of users and groups. If you have any more questions, let us know.