Hi.
So we think we fixed the bug.
Can you please check your customers backup import into 8.4 2017.10.03 version latest build and let us know. It is available on standardinstall.com after you log in as test version.
This is not the issue of upgrade SERP. But serverip.dat in this case contains the value: 192.168.88.12:1301, so this is local IP of the server with SERP.
Anyway I don't understand what do you me...