I needed to pass -c <conf-file> as does not default to /etc/kuhler_1250.conf, missing...
$ lsusb Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 007 Device...
You say re-running causes segfault, any reason why you need to re-run the server?...
Segfault if port 1250 bounded