I've encountered a problem with NetworkManager in that it said that my ethernet connection was not managed. I searched for some fixes, but I guess in the end I screwed it up (edited interface etc.). In the end I've even removed/installed it again (a few times), but not to much success. Now not even the wireless seems to be working anymore (after a reboot). Fortunately, I still have WICD (found it as an alternative to NetworkManager). But I'd like to get NetworkManager back working.. is it possible to reinstall it so that it creates the ethernet and wireless connections again? Because I actually DELETED all ethernet connections in the "Edit Connections menu.." and I don't really know how to set it up again :).
You can check which devices NetworkManager manages with
If your ethernet connection shows up as unmanaged, you should check if /etc/NetworkManager/NetworkManager.conf has your ethernet connection managed = false. This should be true otherwise NetworkManager will ignore this device.
Otherwise you can check network manager says "device not managed".