Android 4.1 to 5.1 Update - WIFI won't stay connected

[AC Question]

When I had 4.1 on my used Moto G (first version) I had no problems, when I get home it's connected. But now that the phone has upgraded from 4.1 to 5.1 I am unable to stay connected to my wifi. I have to go through my router to get it connected and soon after it's no longer connected. I done the many ideas on getting it to connect but nothing is working out for me. I am currently getting a Authentication problem. I have a Netgear DSL router via Frontier - the ONLY phone service out here in the sticks.

 

[B. Diddy]

Welcome to Android Central! Start by rebooting the router. If that doesn't help, review this guide for more ideas: http://forums.androidcentral.com/am...roubleshooting-wi-fi-connection-problems.html