Error: "Unfortunately you cannot configure the disks because Agent has not been deployed to this machine" (4045718)

When trying to protect new machine the error is shown: "Unfortunately you cannot configure the disks because Agent has not been deployed to this machine. Click Next to go to schedule"

Agent software was installed and agent service is up and running

To resolve the issue please install the agent version matching the Core one. Lower version Core is unable to properly communicate with higher version agents.

Either Core should be upgraded (which is not always possible due to replication), or Agent software uninstalled and matching version installed.