If the MountV resource that the RegRep resource is configured for goes offline (or the Volume Manager Disk Group) and the first monitor cycle detecting this is the RegRep then the resource will fault.
VCS ERROR V-16-10051-5503 RegRep:<resource_name>:monitor:Directory does not exist (or) could not create (directory=<regrep_path>)
The storage that the RegRep resource uses to track registry changes has been lost.
Troubleshoot the reasons why the storage is lost.
SFW HA with RegRep resource configured