I think don’t do any updates until monday :)) I did tree times and it was )(^&%(&%@(
but that helpt for me:
Press (Ctrl+Atl+F1) to enter Terminal
Log in in terminal
apt-get update
apt-get upgrade and install updates.
On my girlfriend PC I don’t ever bother to do anything, maybe just next week (then updates will be safe) or she will kill me and ask me to install windows back… 
No, I can’t confirm fix. Still can’t login in KDE.
I’ve made little investigation. The same problem blow up few times before
I’ve found this topic.
[quote]OK, I figured this out.
First I uninstalled lightdm, which removed lightdm, lightdm-greeter, and kubuntu-desktop.
Then when I re-installed lightdm, it added unity and about 96 other packages. Then I re-added kubuntu-desktop.
No joy.
But… I saw an ibus error in the lightdm x-0-greeter.log. I didn’t think much of it because there weren’t any errors in the lightdm or x-0.log.
QInotifyFileSystemWatcherEngine::addPaths: inotify_add_watch failed: No such file or directory
QFileSystemWatcher: failed to add paths: /var/lib/lightdm/.config/ibus/bus
file:///usr/share/kde4/apps/lightdm-kde-greeter/themes/userbar/main.qml:135: Unable to assign [undefined] to QString usersession
lightdm-kde-greeter: Fatal IO error: client killed
I isntalled ibus, rebooted, and everything came up perfectly. I don’t know much about ibus, but something needed it. [/quote]
It seems like my problem I have quite the same issue with /var/lib/lightdm/.config/ibus/bus. But install ibus change nothing and at the end I have no Fatal IO error, it mean that this is quite similar but not exactly the same.
I’ve already reinstall lightdm, lightdm-kde-greeter few times(with purge and remove /var/lib/lightdm/ by hands) and no changes. Is there any bugtracker or something? I can’t use my laptop normally[/code] since Friday.
Any news? :s about this bug?
If you have same problem and you can’t login then you have to do something about it, because it can’t fix by it self. At least I think that even if you have “automatic updates” they can’t update your computer if you can’t even log in.
Maybe I wrong.
I’ve installed all updates. I just checked no changes.:@ Updates possible install without lightdm. Terminal works perfect.
I think you’re completely wrong here.
I think I’ve found the solution from ubuntu questions portal.
[quote]Now run ls -lah. If in the output the line
-rw------- 1 root root 53 Nov 29 10:19 .Xauthority
then you need to do chown username:username .Xauthority and try logging in.[/quote]
This is really helps me :D.
The message you got shows lightdm-kde-greeter don’t know which user-session it should start. That’s defined in /etc/lightdm/lightdm.conf :
user-session=kde-plasma
Could you post you lightdm.conf file ?
It could also be a greeter theme fault, try to change it from userbar to classic
Hi there,
Can you check .xsession-errors?
Also, for people stuck with this, can you switch from lightdm-kde-greeter to unity-greeter and see if it works? If it does we can then pinpoint the problem to the greeter itself as opposed to the whole display manager.
You installed updates and do everything in terminal that means you do something right?! So where I am wrong here ?
The recent updates also would not let me log in. Get to the log-in screen, enter password, and freeze there. I couldn’t get to a terminal from there either for some reason. So what I did was boot into recovery, command prompt. Enable networking from the menu because it will be non functional. Then apt-get update, apt-get install kde-workspace. Reboot and desktop logs in normally. Muon update manager and package manager will need to be reinstalled if you use them.
It was few answers before. СTRL+ALT+Fn(n from 1 to 6) will show you console. And network even wi-fi working( if you set as system connection).
Ok so what is the fix here? I’ve reinstalled many times over the past few days. I can login, then I update. After update I restart, log in, then the log in boxes disappear and nothing happens. I can Ctrl+Alt+F1 and get into terminal. I try and update from there and it tells me something isnt needed, so do autoremove. I do that and try to continue with updates. I reboot and the problem still exists. Has anyone found the fix yet?
I think you should provide logs from your console. Also check rights. for .Xauthority.
umm what? how can I copy logs in terminal and post them here if I can’t log in?
run
$ sudo apt-get dist-upgrade
Ready, is correct.
thank you very much. :D:D:D:D:D:D