Cause 4 of 4: The Wi-Fi access point is using a hidden service set identifier (SSID)
If the Wi-Fi access point is using a hidden SSID you can't find the Wi-Fi access point when you search for available Wi-Fi networks. You can only access networks that use a hidden SSID if you know the correct SSID and have set up a Wi-Fi access point on your phone.
Solution: Key in SSID and security settings manually in your phone.