Windows Server 2012 Hyper-V Replica is a new feature that replicates all changes on a virtual machine to a counterpart virtual machine hosted by a different server. Replica overview and deployment considerations can be found here. This feature is well documented so I'll skip setup and installation and strictly focus on troubleshooting. I received a call from one of my customers who was trying to evaluate this feature for a disaster recovery scenario in test. Unfortunately, any time he attempted to enable this feature an exception was raised. I'd like to share some of the troubleshooting steps we worked though to resolve this case. You may not have this exact issue but the troubleshooting steps should still be applicable.
The customer environment was fairly straightforward, each Hyper-V host was a domain member and for testing purposes the physical machines themselves were actually located in the same datacenter with gigabit connectivity. Since this feature was new to me, I started out by first setting it up from scratch in a test environment using commodity hardware which consisted of a DC and two member servers. Armed with this new knowledge and walking through deployment guide above I felt more confident continuing in the investigation.
Domain - REPLICADOMAIN
DC - REPLICADC
Hyper-V Hosts - REPLICAHOST1 (Primary), REPLICAHOST2 (Replica)
In my customer environment, any attempt to enable replication for a VM returned the following error, 100% repro. Replica uses mutual authentication based on Kerberos or mutual authentication based on certificates for the server (not for the user).