For Subscription licenses, Acronis Files Connect may be installed on an unlimited number of physical Windows-based host servers.
For Perpetual licenses Acronis Files Connect may be installed on one physical Windows based host server. So, you should disable the old server first before specifying the full serial number on the new machine. There are no conflicts between coexisting servers, apart from two servers running with the same perpetual serial number. Please refer to KB 57122 for more details.