If you are going to live migrate from a Hyper-V 2012 cluster to a Hyper-V 2012R2 cluster, the virtual switch name must be the same on the hosts.
We needed to rename the switch on the 2012R2 host, so we just deleted the switch in VMM and recreated it with the same name as the 2012 servers had.
Doing so gave us this error:
Unable to find extension (0d37c9f0-ea6c-47a0-9c42-4baeba3768d1) on virtual switch (Hyper-V Logical Switch)
Verify the extensions installed on the host and retry the operation.
Searching the Internet did not give us any leads.
Ran: Get-VMSwitchExtension -VMSwitchName “Hyper-V Logical Switch” | select id
This returned the IDs from the extensions attached to the virtual switch, and we saw the ID from the 25230 error was missing.
Uninstall the DHCP extension from Add-Remove program. It was not removed when the virtual switch was removed.
Creating a new virtual switch added the DHCP extension back to the server.