This is on 1.2.0-rc1. I have another cluster (running 1.1.1, where the backup target was set successfully on an older version of harvester) where I cannot apply the backup target currently configured with the same error, but initiating backups works fine.

This was not too surprisingly an issue on my end. The client definitions in /etc/exports on the NFS server weren’t correct. nfs mount command not exactly giving a stellar error here, but certainly not a rancher issue 👍