HyperV replication fails

I have a servers with replication turned on. Had to install windows- and HW-updates. Live migration functioned exceptionally well and updates were a breeze.

But, turning on the replication was not easy. I got an error: “Replication failed”. Went to event log and saw this:

“The description for Event ID 32000 from source Microsoft-Windows-Hyper-V-VMMS cannot […]