ubun2

I had a similar problem.

In my case, I changed the SSID and the password. And for some reason when I entered the new details, it didn't replace the old SSID and password. I changed the following files manually and it seems to work now:

Files chaned

/etc/wpa_supplicant.conf

/etc/wpa_supplicant/wpa_supplicant.con

Change the old SSID and password to the new ones and hopefully should work :)