Cannot login to any TTYs - Wrong password

Perhaps your keymap configuration is wrong fo the tty (which is a different setting than Xorg / Unity) and your password is wrong because of this. Try entering your password when you're prompted for your username and see if the characters turn out right; don't press enter, but delete your input (since login tries get logged and your password would be in that logfile). If something is wrong, you must set the keymap. In unity, open the terminal application and enter

sudo dpkg-reconfigure console-setup

and choose the right layout there. You might have to reboot.

The most common cause of this error is simply typing your password (or username) wrong. The keymap in the console is often subtly different from the one in X.

Make sure you're typing the correct password by first typing it in the login field where you can see if it's being written as expected.

Check that you're typing your username exactly as it should be (including case), by comparing it to the output of whoami run in a terminal.

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Another thing that will cause this exact same error message is if your login shell is not listed in /etc/shells. Find which shell you're using by searching for your username in /etc/passwd:

grep "dave" /etc/passwd

(replacing dave with your username) you should see something like this:

dave:x:1000:1000::/home/dave:/bin/zsh

The last field (/bin/zsh) is your shell. Let's search for it in /etc/shells:

grep "/bin/zsh" /etc/shells

We should see something like this:

/bin/zsh
/usr/bin/zsh

But if you don't, that's what the problem is. Try re-installing zsh (or whatever shell is missing from /etc/shells), and if that doesn't work, add it manually:

echo `/bin/zsh` | sudo tee /etc/shells

(we use tee because > redirection doesn't work with sudo)