In this guide, I will be showing you how you can fix the 'device not managed' error when trying to customise a network adapter.
The first thing you will need to do is to open the terminal. Once in the terminal, type in
sudo nano /etc/NetworkManager/NetworkManager.conf
Once you are in the config file, you will see the following
You will need to change the bit where you see
You config file should now look like this
You can now save and exit the config file by pressing Ctrl + O followed by Enter and then Ctrl + x to exit.
You can then apply these changes by typing
sudo service network-manager restart