Linux Network Management disabled after reboot

Problem: Network Management was disabled after a reboot and no way to enabled it again via GUI on task list (it were running). The issue was caused by NetworkEnabled=false. Use an editor, kate, gedit or similar.

sudo kate /var/lib/NetworkManager/NetworkManager.state

Change the following line it back to NetworkEnabled=true

Restart the network management program

sudo service network-manager restart

It should now work fine again. For more details see the bug report