I am experiencing problem on our DC which is a VM hosted inside ESXi 5.5. Upon checking on the event logs I'm seeing this error before the DC stops responding, in which in return I need to restart from ESXi the DC Guest OS for it to be able to run again.
This computer was not able to set up a secure session with a domain controller in domain XXXXX due to the following: The RPC server is unavailable. This may lead to authentication problems. Make sure that this computer is connected to the network. If the problem persists, please contact your domain administrator.
ADDITIONAL INFO
If this computer is a domain controller for the specified domain, it sets up the secure session to the primary domain controller emulator in the specified domain. Otherwise, this computer sets up the secure session to any domain controller in the specified domain.