PeakHour says UPnP can't be initialised, but I've already closed all running apps

For PeakHour to be able to auto-detect UPnP devices, it must be able to listen on a special broadcast port on your network (1900/udp). Only one app can be listening on this port at a given time, and in some cases other applications keep the port open even though they don’t appear to be running.

If you get the error that UPnP can’t be initialised and you have no other apps running, check the following:

• If you run Elgato EyeTV, try opening EyeTV → Preferences → Sharing and disable the option Share my EyeTV Archive.

• If you’re running the Sonos app, close it.

If you’re not running either of those apps, issue the following command in Terminal to reveal the app which has the port open:

sudo lsof -i -P | grep :1900

This should show output similar to the below:

PeakHour  70655       userid    7u  IPv4 0x2b5d2afa8b1a76ed      0t0    UDP *:1900

The name of the app which has the port open is in the first column (in the example above, it is PeakHour).

Try quitting the named app and relaunching PeakHour.