See post 13 in the FAQ thread linked to above.
If you get those with an ID rather than a device name, this is most likely an orphaned device - you can check in My Devices whether you actually do have a device with that ID. If not, you can remove it by following these steps (I just did that to remove the ten or so orphaned devices I had and after three more network repairs, I was able to get the network repaired without any errors): Go to My Devices Click “New Device” at the top right Enter some obvious name (I just used “Trash”), put the orphaned network ID into the “Device Network ID” field, select “Z-Wave Device” as the type, and select your location and hub Click “Create” In the mobile app, go to this newly created device (you might have to refresh the device list), select “Edit Device” and force-remove the device This will rem…
If that doesn’t work, contact support.