The Live-Tile shows a different amount of information depending on the DPI level of your screen. It can show you the following information.
Link-Speed (not available on every device, on some the max. speed is not available)
Public IPv4 or IPv6 (depending on your connection)
Encryption (only on the large tile or in case the link speed is not available)
SSID/BSSID of the Access-Point (including the manufacture if available)
Private IPv4 or IPv6 (depending on your connection)
In case you see "Unknown error (BSSID)" instead of the BSSID, you'll find the answer in my "Connect to networks tutorial".
You see this message if there is no Wi-Fi adapter found!
Error messages explained (Wi-Fi adapter not found)
You see this message if there is no internet access detected!
This can have a number of reasons, most likely with Windows 10 itself. You also need the PRO version for Live-Tile support (but you can test it first for a few hours).
Maybe one of these solutions fixes the problem:
Restart your device.
Look in the settings in my app whether Live-Tile it enabled.
Look in your privacy settings under "Background tasks" whether this app is blocked.
Try reinstalling the app.
If you see "UNKNOWN ERROR" in settings, the initialization of the Live-Tile or the background task failed/was blocked for some reason.