Error establishing a database connection – WordPress Multistage in Sub-Folder

Hi all.

I have a website running on my production server which I moved to localhost.

The folder structure is as follow:

localhost/xxx/main – Here are the website files.

I have updates the database by changing all the url’s to be localhost/xxx/main.

My .htaccess looks like this :

RewriteEngine On
RewriteBase /xxx/main/
RewriteRule ^index\.php$ – [L]

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ – [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
RewriteRule . index.php [L]

wp-config.php has the following lines added :

/* Multisite */
define('WP_ALLOW_MULTISITE', true);
define('MULTISITE', true);
define('SUBDOMAIN_INSTALL', false);
define('DOMAIN_CURRENT_SITE', 'localhost');
define('PATH_CURRENT_SITE', '/xxx/main/');
define('SITE_ID_CURRENT_SITE', 1);
define('BLOG_ID_CURRENT_SITE', 1);
/* That's all, stop editing! Happy blogging. */

The problem I am having now is that I cant establish the connection to the database.

Whenever I set up
define(‘MULTISITE’, false);
the connection with the database is being established just fine.

Any ideas please?

Thanks

Dom