Installed domain-based Multisite but can’t access wp-admin (redirect loop)

I’ve installed a domain-based Multisite on my server, and everything works including each of the subdomains. Here I should explain that I imported a Database that was on my Local Mac, and then changed the details in the database for each site. However, I now can’t access wp-admin for the main domain or any of the subdomains, Chrome just tells me there is a Redirect Loop (http://cl.ly/Qg7K). Let me just clarify that I can’t access wp-admin at all, i.e not even the login page.

I’m reasonably confident with WordPress, Databases and servers, so I can most likely get any data back for you and carry things out to test, try to fix etc.

Thanks for any help!

EDIT: People asked for my .htaccess code. It was copied from my localhost installation but I was using a Virtual Host so there were no paths involved. I’m no expert with .htaccess though so something could be wrong.

RewriteEngine On
RewriteBase /
RewriteRule ^index.php$ - [L]

# uploaded files
RewriteRule ^files/(.+) wp-includes/ms-files.php?file=$1 [L]

# add a trailing slash to /wp-admin
RewriteRule ^wp-admin$ wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^(wp-(content|admin|includes).*) $1 [L]
RewriteRule ^(.*.php)$ $1 [L]
RewriteRule . index.php [L]