When organizations are enabled for the K1000 appliance, it is possible to configure the appliance so that the user can switch from the K1000 AdminUI to the SystemUI (and/or to the K2000, if the appliances are linked).
In order to do so, the SystemUI administrator accounts (which are local, not AD-derived) must be manually updated each time an AD password change occurs.
In the SystemUI, go to Settings>Administrators. From the list, click on the user account in question and update the password on the Administrator Detail page. Save.