For PeakHour to be able to auto-detect UPnP devices, it must be able to listen to a special broadcast port on your network. Unfortunately only one app can have this port open at a time. In some cases, other applications keep the port open, even though they aren't running.
If you get this error that UPnP can't be initialised and you have no running apps, 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 Controller app, close it.