Application Enablement Services r6.1.1: Communication Manager r6.2.
As an overview, the customer had moved locations and changed the IP addresses of the AES, NICE recorder and a G650 cabinet. These issues persisted after the IP address change.
NICE recording extensions would not register. From the AES side, the registrations would continuously be in a REGISTERING state. From the NICE side, the error message “Expect to get CM_RST_REGISTER_DEVICE BUT GOT CM_RST_FAILURE” as seen below:

From the Communication Manager side run this command while NICE virtual extensions are trying to register:
'list trace ras ip-address <aes-ip-address>'
14:06:29 denial event 2041: IP RRJ-No DSP Resource
endpt 10.20.115.31 data0:0x0