I am in the process of cross forest DC migration with an environment of 400 users, first I have configured the GPO to add the dns suffix search domains to the current clients of the old domain however upon applying policy I get The RPC server is unavailable or RPC was cancelled or access denied sometimes.
I have checked the domains (4) health , replication and all looks very well. I checked the DNS as well and there seems to be no issues what so ever.
I connected to one of the clients that has an issue to make sure these clients are joined to the domain and using the proper DNS list. then checked if the domain has the correct hostname as it appears in the domain and everything looked fine.
I disabled Kaspersky firewall on the client and disabled Windows firewall client but still the same issue occur .
When trying to connect to any of these clients with hostname to browse to the C$ folder it gives an error, I also tried with the FQDN and had the same problem but with IP it connects fine.
I checked the RPC service, Computer browser service to see if they are running and they were running.
I am attaching screenshots of the GPO policy and the error that appears when trying to browse to the client folder C$ with hostname or fqdn.
I am out of options and would appreciate if someone could point me to a solution.