A network administrator uses autoregistration to register IP phones to Cisco Unified Communications Manager. Later, the administrator changes the DN of the autoregistered phone to free the DN in the…

A network administrator uses autoregistration to register IP phones to Cisco Unified Communications Manager. Later, the administrator changes the DN of the autoregistered phone to free the DN in the autoregisteration range. After a certain amount of time, the phones fail to autoregister, displaying "Error DB Config" or a similar message on the IP Phone screen. What is the root cause of this issue?