synergy-win_x64-v3.0.73.7-rc2: "WARNING - failed to meet start conditions: Server IP not set"

[Paul Gardiner 0]

I've just installed Synergy 3 on a Windows 10 machine and a Windows 11 machine. I can't get either to see the other (or to manually connect). On the Windows 10 machine, the logs show the warning in the title, and the "server active" message never appears. Also the troubleshooter shows synergy-core.exe failing to run.

I uninstalled and reinstalled, between the two steps deleting every Synergy directory and registry entry I could find. No luck. Any known workarounds for this?