Turn off Bluetooth while doing the device scan. Bluetooth headphones show up as serial ports, and they crash the system when we try to close them again. This is already fixed for the next release.
You might also find it better to connect the mac with an Ethernet cable anyway. MacOS ships with a serial port driver that conflicts with the one used by Ruida controllers. It can be fixed, but it’s a bit of mucking around on the command line to do it, and connecting with Ethernet isn’t hard (and it’s faster).