Unable to logon to Ubuntu

Question

I am not able to login to Ubuntu. It is booting like normal but getting hung showing the wallpaper, without any panels loaded. The cursor turns to waiting circle (hourglass equivalent) and nothing happens. How can I troubleshoot.

P.S I have set to logon automatically without prompting for password. Before the restart, I had installed Docky.

EDIT 1: I logged on to console (recovery mode) and removed all startup applications I added from ~/.config/autostart but it didn't help.

EDIT:2 I removed Docky. Still not logging in. Panels are not getting loaded and Alt+F2 doesn't work

Answer 1

I suggest, you boot your computer and wait, until your login hangs. Then you press Ctrl+Alt+F1 to get to the console and login there. After the login, move your entire home directory to a backup location and create an empty directory (sudo mv /home/ijeeves /home/old.ijeeves && sudo mkdir /home/ijeeves && sudo chown ijeeves:ijeeves /home/ijeeves).

This way, all application settings are removed from the normal place and you start with a blank account. You can move some of the directories containing the settings (starting with a dot) back to your new home directory, once you can login again.

If your home directory is encrypted (enter mount into the console and look for something like /home/ijeeves/.Private on /home/ijeeves type ecryptfs), you cannot use the solution above. Create an old directory inside your home directory (without sudo) and move all files and directories starting with a dot into that old dir.

mkdir old
ls -a # lists all files & dirs
mv a* b* c* d* e* f* g* h* i* j* k* l* m* n* o* p* q* r* s* t* u* v* w* x* y* z* old
ls -a
mv (remaining dot files & dirs) old

Answer 2

If you let it try to boot normally and run until it hangs, are you able to press Ctrl-Alt-F1 and bring up a console log-in prompt? If so, can you log in to that console?

If you can log on. Try creating a new user from that terminal and then logging in the normal way as the new user with a clean account:

sudo useradd -m temp
sudo passwd temp
sudo restart gdm

If you can pick the temp user, log in as temp and it comes up fine, then your settings are at fault in your home directory and you need to figure out what to delete to get back to a default state of settings.