I made the mistake of removing the user login block through the web interface, and logged out.
Now, I don't have the login interface anymore. Does anyone know how to solve this or is re-installing the only solution?
Furthermore, when I access example.com/user, the log-in form is shown, but it doesn't accept my credentials anymore.
I think I have found the "issue": The login page on mysite/user is the default login page for mysite; however, the default login block that is displayed on the front page is the login for the Drupal 7 web interface. These two are completely separate, that is why my credentials weren't working on mysite/user.
So in conclusion, if you removed the default login block and logged out of the drupal 7 web interface, then you are in troubles.
Please correct me if I'm wrong.