I got the same problem today.

TLDR: downgrade libnl3 or upgrade network-manager .

As per this answer, problem is that a fix in libnl3 caused a regression in network-manager . Then, it was only a bug for -proposed packages, but I guess bug was tested enough that it could be introduced into regular Ubuntu ;).

Safest way is to take a step back and install earlier versions of libnl-3-200 libnl-genl-3-200 libnl-route-3-200 (see details in said answer).

This leaves you with downgraded packages. Remember to not upgrade them until relevant upgrade for network-manager is available.

Alternatively (I did this), you can take a step ahead and install newer version of network-manager : for amd64 or for i386. You can download package on different system and pass it with USB stick. Or download it with your smartphone and pass it via USB.

Install it with:

sudo dpkg -i network-manager_*.deb

You can try to get networking by just restarting NetworkManager:

sudo service network-manager restart

But I needed to reboot to get systray applet back.