I'm a newbie in using ubuntu. Yesterday I was installing a few packages. During the process, at certain point the sudo command did not work anymore. So I rebooted, and it just stuck at booting page. I tried to search solutions online, got into recovery mode, tried a few things. Nothing works. Now when I reboot, I get error messages saying "Failed to sart Network Manager. Failed to start login servcice. "
I don't want to reinstall the system. What can I do now?
Any help would be greatly appreciated! Thanks!