Earlier today I installed the Screen Shot app "Screencloud" and after the installation Firefox was having problems. I didn't think much about it, just closed Firefox, then proceeded to change the toolbar opacity on Ubuntu Tweak.
After restarting my system, hoping it would fix Firefox (because, you know, restarting fixes everything ;) ) I am able to go to the Log In Screen, type in my password, but then I get 3 errors regarding the Screencloud Ubuntu One, Imgur, and Dropbox plugins. After clicking the "Okay" on all three errors, all I see is my wallpaper. I am not able to access the terminal VIA Ctrl>Alt>T, but I am able to log out VIA Ctrl>Alt>Delete.
I have tried all desktop environments I have installed (that, except for Unity 2D, has to do with Cairo Dock.)
I hope I have provided enough information. If you need more, please ask. Please help! I would like to not have to re-install Ubuntu.
OS: Ubuntu 12.04
I also have a Ubuntu 12.10 Live USB, but Ubuntu 12.10 hasn't run very well on any of my computers.