If you have already finished installing Drupal, this either means that the username and password information in your settings.php file is incorrect or that we can't connect to the MySQL database server. This could mean your hosting provider's database server is down.
The MySQL error was: User sciencecodex already has more than 'max_user_connections' active connections.
Currently, the username is sciencecodex and the database server is localhost.
Are you sure you have the correct username and password?
Are you sure that you have typed the correct hostname?