Ubuntu not loading after login screen after an incomplete upgrade of 15.10

Question

Recently, I tried to upgrade the ubuntu version 15.04 to 15.10. I think I couldn't complete the installation completely. Now the problem is I'm not able to login from my login screen which showing as 15.04. When the password is given, the screen will appear as it is without any desktop icons and sometimes no cursor. But i could do a restart or shut down from the screen if I haven't provide a login password. I tried even terminal also but there shows login incorrect when the password is given.Also there it is showing as ubuntu 15.10

I have a DELL vostro 3446 with Nvidia drivers GT 820M. Once there was a problem of continuous restarting and got solved by using an alternate driver.

How to sole this issue? Anybody can help me? I'm really afraid of updating my system now. every time it ends up with such kind of issues.

Answer 1

Are you using gdm? If so, try switching to lightdm:

sudo service gdm stop && sudo dpkg-reconfigure lightdm
sudo service lightdm start

It could also be an issue with the permissions on your .Xauthority file. To solve that, refer to this question: https://askubuntu.com/a/223634/470880

However, if you believe that it was an upgrade issue, perhaps using a USB/CD to re-install Ubuntu 15.10 would fix the issue.