I have the exact same problem.
- Installed Compiz Settings Manager and Unity Tweak Tool
because Unity was not responding properly.
- Consequence: Nothing shows, no dash, no bar, nothing... just a wallpaper and the mouse.
- I tried following this same post: Difference between Login in Ubuntu 14.04 tty1 and Initial Login
- I can't log in to tty1. It says my login is incorrect, but I am typing it right with the good password.
POSSIBLE SOLUTION
If you have numbers in your password we might be in the exact same situation. I read on this page Cannot login to any TTYs - Wrong password that NumLock might not be on and might be causing this problem.
Information about how to install NumLock.
https://help.ubuntu.com/community/NumLock
In my case, I can't find a way to install NumLock following the steps on that page. Via the System Settings, when I click on Keyboard Preferences everything disappears and I am stuck with just the wallpaper. And I can't open the terminal (CTR + ALT + T does not work). Plus, I can't login to any tty.
(I have to admit that I am more than a newbie and know almost nothing about computers and linux, I just searched forums and read them a lot to come up with all that. So everything here might not be good.)
Let me know if this helps and if any of you have tips on how to fix my situation in the mean time.