I have input my password for WiFi connection but it's showing authentication problem. please help

Where did you find the password?

I'm asking because some routers have a label showing the password which is the one you need to log in to the Settings pages. What you need to connect is the Wireless Security Key and that isn't always on the label.
 
I think there was an issue with the newest update for Android - I have had this issue now for 2 weeks with my work WiFi that I had no problems connecting to prior to a recent update. I have tried everything and nothing seems to work to fix this issue.