It seems as though NetworkManager fails to start at the point where it would read /etc/network/interfaces.
Let's try to clean up some things just in case: please take a backup of /etc/network/interfaces (say, to your home directory using 'cp /etc/network/interfaces ~/e-n-i.backup'), then remove all the comments from it. Ideally all that should be left are the entries for lo and eth0, like so:
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp
Reboot, then make sure network-manager is really stopped:
sudo stop network-manager
Finally, start network-manager again with the following command:
Thanks for reporting this bug.
It seems as though NetworkManager fails to start at the point where it would read /etc/network/ interfaces.
Let's try to clean up some things just in case: please take a backup of /etc/network/ interfaces (say, to your home directory using 'cp /etc/network/ interfaces ~/e-n-i.backup'), then remove all the comments from it. Ideally all that should be left are the entries for lo and eth0, like so:
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp
Reboot, then make sure network-manager is really stopped:
sudo stop network-manager
Finally, start network-manager again with the following command:
sudo /usr/sbin/ NetworkManager --no-daemon --log-level=DEBUG --log-domains= USER_SET, SYS_SET, CORE,DEVICE >/tmp/nm.log 2>&1 &
NetworkManager should start up and write debug information to nm.log. Please get that log from /tmp/nm.log and attach it to this bug.