[Solved]Stopping an Activity prevents Kubuntu from booting properly

[Guest]

Hello there, I'm having a big issue with activities.

I never used them until some hours ago, when i was thinking "Let's see how they work".

Basically what i did was:
1)Creating a new "empty Desktop" activity.
2)After some time i opened the "activity manager"(or how it is called in English, the one where you choose to create new activities, remove them or whatever). And i, alas, stopped this new empty desktop activity.
Suddenly all went dark. the only thing left in my screen was the mouse going around lonely.

I rebooted the PC(using Ctrl+Alt+F1 -> sudo reboot), and now kubuntu can't boot properly.
It stops at some message about AppArmor profiles(so i can't even see the login screen).

Any help would be appreciate.

PS:
I have installed kubuntu with /home in a separate partition from /, thus, if i have to I'll eventually reinstall kubuntu, but i hope i wont need to do this.

[dibl]

Re: Stopping an Activity prevents Kubuntu from booting properly

I don't know why playing with desktop activities should cause such a KDM failure. However, here are some things to try:

Boot recovery mode, and on the recovery menu, choose "Drop to root prompt". At the root prompt, enter

service kdm start && exit

Now watch the messages and see if you can see an error.

If it still fails, there is a log file at /var/log/Xorg.0.log that may reveal something about the failure to run X.

[Guest]

Re: Stopping an Activity prevents Kubuntu from booting properly

I've tried to run that command but i didn't receive any output.
Later I'll try to post some lines from the log file, maybe some1 can understand what's going wrong.

In the meantime I'll try to disable AppArmor, just to see if, with it disabled, the loading procedes further.

Thank you for your help.

Edit:
I've tried to disable AppArmor but nothing changed.

Anyway i think i found out something reading from the log files.
some time before this happened(more than 1 hour before i think) i changed some settings about my NVIDIA graphic card . Probably this causes the problems with X, which can't find any screen.
Sorry for not mentioning this before, but, as i said, more than 1 hour passed between the settings change and my problem, thus i didn't realize these facts were connected.

edit2:

I was able to solve this issue renaming /etc/X11/xorg.conf to /etc/X11/xorg.conf.old