PCD Migration fails with DNS invalid or not reachable though the DNS IP is reachable also DNS record is valid,  we are ending up with unsuccessful migration

Could someone help me with the Certification 500-052 UCCXD. is this still continued by Cisco.  please advice if I can attempt for this in May 2023

Supervisor unable to change Business days in Calendar Management.It says "Date must be a future date."  

CSCvq24058-Historicaldatabasequeue is full.We are still getting alert on version 12.5. whats the resolution for this?.

Is it possible to achieve below Call forward Scenario in Cisco. Call forwarded while not answered, device unregistered or  CTI Failure. 1. Calls to "A"  -> forwarded to "B" -> Forwarded to "Hunt_1"2. Calls to "B" -> forwarded to "C" -> Forwarded to "...