Wifi problem validating identity
Start by verifying that a wireless access point (AP) or router is nearby and actively offering Wi-Fi service.
Always start here, using another Wi-Fi client to determine which is the likely culprit, the network or the client.
The AP/router and client must use compatible 802.11 standards.
Please note the following: To determine which 802.11 standards your wireless network’s AP or router supports, look for “Wi-Fi certified” logos, or search for Wi-Fi certified products at the Wi-Fi Alliance website.
Properly connected Wi-Fi takes precedence over mobile broadband, but it can be helpful to disable your device's mobile network connection while debugging Wi-Fi.
Note that whenever you're trying to connect an Android Wi-Fi client to any network name, status is displayed on the Wi-Fi Settings panel, in the row labeled Wi-Fi.
Tap Settings If Wi-Fi is off, tap the slider to turn Wi-Fi on.
When Wi-Fi is on, a signal indicator appears at the top right corner of your home screen.