I'm glad the OP got their WIFI back up and running after re-install of the OS. I agree your machine could have suffered packet loss or file corruption. I felt the need to post this PSA, for those who might miss it. Have a look at my screenshot...
I have a modern computer with Gen6 WIFI hardware. Notice how I am getting the same as you were? Do you know why? I have my WIFI toggled off. Upper right hand side of the window, click toggle to turn on WIFI.
I use Ethernet for supreme security, stability, & speed. 
