Try checking your site’s error logs for a more specific error message. Your hosts should be able to help you in accessing your site’s error logs.
I have found this:
[Fri Jul 19 18:52:06 2013] [error] [client 127.0.0.1] File does not exist: /services/users/d3b95a67-5f91-42d6-9197-50168e5e6de0/wizzyweb/www/stevenage50plus.co.uk/feed
[Fri Jul 19 18:52:12 2013] [error] [client 127.0.0.1] File does not exist: /services/users/d3b95a67-5f91-42d6-9197-50168e5e6de0/wizzyweb/www/stevenage50plus.co.uk/page
I get the same on Chrome, Firefox, Safari and Explorer.
This has nothing to do with web browsers. Right now, no one can reach your site. contact your hosts.
My hosts tell me it is a database/wordpress problem.. It all works fine before I input my database.
Now I have named the normal theme again it shows (minus images I am yet to upload).
Which part of:
Firefox can’t find the server at stevenage50plus.co.uk.
are you having a problem with? This is a server/domain name issue. It has nothing to do with WordPress.
WORKAROUND RESOLUTION FOUND:
We looked at Lee’s installation and we could replicate the issue. We noticed however that by navigating directly to a deeper link within the admin system, that we were in fact logged in.
It’s as if we are authenticating and even though correctly authenticated we are being redirected to the no access page, if we navigate to http://whatever/wp-admin/options-general.php we are then redirected to login page, then when we login we succesfully go to dashboard and issue vanishes.
The workaround was to put a redirect in the .htaccess file which looked like
Rewrite Rule /wp-admin -> /wp-admin/options-general.php
