Connection 802.1x supplicant failed

Solution 1:

It might be because you installed some other network manager like wicd along with gnome-network-manager as this exactly was the problem in my case now assuming the same here is what I suggest:

1. Install NetworkManager:

   sudo apt-get install network-manager-gnome network-manager
   

2. Then remove WICD:

   sudo apt-get autoremove wicd wicd-gtk
   

3. Restart your system.

4. Confirm everything is working, then remove WICD config files:

   sudo dpkg --purge wicd wicd-gtk
   

Solution 2:

I had to install WICD because I haven't found the permanent solution for my Linux Mint 18.1 WiFi problem, even though I've made all the updates and every try suggested... so just using WICD or do:

sudo service network-manager restart