Ubuntu gets stuck in a login loop

When I rebooted my Ubuntu machine it started to repeatedly ask for the password.

When I entered the correct password, the screen went black and asked for the password again.

The problem was an error in the ~/.profile file.

To log into the Ubuntu terminal

1. Press the Ctrl-Alt-F3 key combination
2. Enter the username
3. Enter the password
4. Open the ~/.profile file with

   /bin/nano ~/.profile

Make sure the

• The syntax is correct, all open braces are closed,
• All PATH= statements have :$PATH at the end.