InvalidRegistrarAction
Example
{
	"code": "InvalidRegistrarAction",
	"target": "Unknown",
	"details": [
		{
			"code": "InvalidRegistrarAction",
			"number": 43,
			"message": "You may not create users with this security role / account combination.",
			"description": "You are not allowed to create users in the account -0- with security role -1-.",
			"faultCode": "Client",
			"helpLink": "http://developer.avalara.com/avatax/errors/InvalidRegistrarAction",
			"severity": "Error"
		}
	]
}
Explanation

This indicates that you attempted to make a change to a system account or grant an account system admin privileges. This feature is restricted.