Recently I was setting up DHCP High Availability.
All was going well, I had set up DHCP Services on my Standby Node and configured the DHCP Failover Relationship with my first DHCP scope.
All until I started to get the error below
Add-DHCPv4FailOverScope : Failed to update failover relationship MyRelationship on server MyServer
Category info: Object not found: (MyRelationShip:root/Microsoft/…v4FailoverScope)
After some digging, this problem occurs where you have custom options set on your DHCP server and inside your DHCP scope.
To fix this. On the new standby server, open DHCP > Right click IPv4 > Set Predefined Options and add your options as required.