Error displaying the error page - Joomla issue

This is usually an error reporting problems connecting to database
So it is a good start to...

1. Check you configuration.php file
2. The database name in your configuration.php must match that of what is configured on your hosting account
3. The database username in your configuration.php must match that of what is configured on your hosting account
4. The database password in your configuration.php file must match what is configured on your hosting account
5. The database hostname in your configuration.php file must match what is configured on your hosting account - usually localhost will work and 127.0.0.1 will give the above error.