Can't login to Ubuntu after update

[The_Explanation]

I have been running Ubuntu very well for around a year, until an update caused me to be unable to log in. I didn't want to take the time to find a solution, so I simply installed Mint in a new partition. Unfortunately, a month later Mint started having the same problem. I can't even get my data off of my Ubuntu partition as I encrypted my home folder. I would like to recover that at the very least, but preferably I would like to be able to log in again since I'm stuck with Vista right now.

When the computer starts, the log in screen is an off white with blue highlighting, different from what it usually is. In the upper right hand corner, it says, "Install problem! The configuration defaults for GNOME Power Manager have not been installed correctly. Please contact your computer administrator." I tried package repair in recovery mode to no avail. I can log in to the CLI in recovery mode, but not the GUI.

[kc1di]

Hi,

Try going to the CLI in recovery mode log in as root and type gdm3 see what happens

[The_Explanation]

"gdm3" returns command not found
"gdm" brings up the same login screen as when I startup normally.

I forgot to mention that I can click on my user name and type in my password. When I press enter, the login box disappears for awhile and acts like it's going to log in, but the the box reappears.

[reed9]

From the CLI type

startx

If the X server is failing to start, that should at least give you some output to help troubleshoot.

Also post the contents of the file /var/log/Xorg.0.log

[kc1di]

Try what Reed9 says.

[The_Explanation]

X started with no problem on that command! For some reason, the log file won't post. I guess the text is too long? I tried uploading it as an attachment also, but the size was too big and then I put it on Rapidshare but my post count isn't high enough to post an external link! So, rapidshare's url plus files/450493858/Xorg.0.txt is where it is.

[reed9]

Well, since it starts with startx, it isn't X or a graphics driver problem, which is sort of what is sounded like initially.

Which leaves me at a little bit of a loss. There might be something in /var/log/messages to shed light. You can try pastebin, I'm not sure what it's size limit might be.

Since you can get on, you can at least backup your important data as well.

[kc1di]

Will the system let you log on as root?
if it will I believe it may mean your home directory has been corrupt in some way.
do you get any error messages while it's trying to boot?

[kc1di]

Another thought , since you can get to a CLI as root you may want to try to do an upgrade from there it may correct the faulty package.

Try this apt-get update
followed by apt-get upgrade

if that does not work , that is it will not do the upgrade
Try dpkg --configure -a

[The_Explanation]

It's fixed! Although I'm not quite sure how...
While logged in as root, it complained about the disk being full, so I moved my Mint partition onto an external, which accidentally removed GRUB. After I reinstalled GRUB, Ubuntu booted with no problems.