Can you clarify what this means? This is a little confusing.
If you're WiFi wasn't working, you wouldn't be able to access anything online (unless of course you're on a data network of sorts). Plus, given that you get an error message about incorrect credentials, this isn't the issue. What if you try to login in through Safari.
By the way, as an aside, you're running 8.1.3, not 8.3.1.