I recently switched from a MacBook Pro to a MacBook Air. Roon Arc worked well before, but after the change, it no longer works.{ "ipv4_connectivity": {"status":"NetworkError","status_code":502,"error":"error: Error: connect EHOSTUNREACH 46.aaa.bbb.ccc:55002, response code: undefined, body: undefined"}, "external_ip": {"actual_external_ip":"46.aaa.bbb.ccc","actual_external_ipv6":"null","router_external_ip":"null"}, "natpmp_autoconfig": {"status":"NotFound"}, "upnp_autoconfig": {"server_ip":"192.168.1.1","found_upnp":true,"error":"
s:Client UPnPError
718 The port mapping entry specified conflicts with a mapping assigned previously to another client
When you moved the Roon Server application to the new server, it tried to use uPnP to confgure port forwarding for port 55002 to forward to the new server but, it is likely that the old Roon Server had already configured port 55002 to the old Roon Server. Thus the router could not honor the request from the new server because port 55002 had already been forwarded.
If you have stopped the Roon Server application from running on your old server machine, you may be able to resolve this simply by rebooting your router. This would clear out the old uPnP managed port forwarding and allow the new port forwarding to be set up.
If this does not work, then just change the ARC port from 55002 to, say, 56000 (or any other port in the 1025 to 66535 range that is not already being used) for the new Roon Server on the Roon → Settings → Roon ARC page. This should also resolve the conflict with the port forwarding rule left over from the old Roon Server even if that old server is still running but is unauthorized.
In addition to what @Wade_Oram said, moving the Roon Server to a new machine (as well es tainting a backup on the same server) currently requires a reinstall of ARC on the phone, followed by a new sync. (Known issue, Roon Labs are working on improving this).
I.e., you probably have to do this after fixing the port issue as explained by @Wade_Oram
