Unmanaged network icon - Network manangement disabled

Solution 1:

I find this happens after a bad shutdown. Just change

managed=false

to

managed=true

in /etc/NetworkManager/nm-system-settings.conf

Note: In newer versions of Ubuntu, the file is at /etc/NetworkManager/NetworkManager.conf

Solution 2:

This worked for Ubuntu 17.04

sudo touch /etc/NetworkManager/conf.d/10-globally-managed-devices.conf
sudo service network-manager restart

Solution 3:

I've just upgraded from Ubuntu 16.04 to 16.10. After that, this problem started to happen to me. In my case, I've solved it following the suggestion given in Ubuntu's launchpad:

touch /etc/NetworkManager/conf.d/10-globally-managed-devices.conf

This creates an empty file.

Solution 4:

You should look at the contents of the file /var/lib/NetworkManager/NetworkManager.state. It should look something like this:

[main]
NetworkingEnabled=true
WirelessEnabled=true
WWANEnabled=true

Change any from 'false' to 'true' to re-enable networking. It may work better if you first stop NetworkManager:

sudo stop network-manager

And start it again once done. Or reboot :)

In any case, this is frequent when a suspended system fails to wake up. It should be fixed in Maverick.