Your Joomla! website has the backend administration access restricted to your computer (via IP address) so that only you can access the login screen.
Your IP address is not permanent and be changed automatically by your internet service provider. You will see the following message when you try to access your administration login (i.e http://www.yoursite.com/administrator)
Forbidden
You don't have permission to access /administrator/index.php on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
To fix this issue :-
- Visit whatsmyip.org to get your new IP address.
- Log into your web host control panel (i.e www.yoursite.com/cpanel).
- Choose file manage.
- Browse to the administrator sub directory in your domain.
- Check the box next to .htaccess then click edit to show the current restrictions.
- Update the ip address then click save
- You should now be able to access your administrator page