Guys, I have had some chat here before about this one but Im still trying to get to the bottom of it. There is no impact to services but I see a lot of errors on a clients FAS servers (2 per DC), all configured as subordinate CA's. All FAS servers are configured to use any of the 4 FAS/CA machines. The errors are related to an RPC failure, there is no firewall on the traffic between sites as far as the VDAs, SF and FAS/CA goes. Whats interesting is, when these errors appear, it shows the RPC error / cert issue failure on the 3 other FAS/CA servers, then the local FAS server manages to issue the cert without issue. This all happens in under a second so there is no issue for the users... I have run RPC checking scripts between FAS/CA, SF and VDAs across both sites, all show to be listening/working. Anyone got any ideas on what else I can check? While not an issue the concern is this issue could affect resiliency, cheers