Sorry, this CMS installation does not support the URL extranet-hosting.co.uk, even though your web server redirected you here.
If you have administrative access, you can possibly sort this out by adding a site to your Site Registry. Do this by visiting Admin -> Site Registry.
Failing that, and if you have direct database access, please ensure that the tables 'tribalcms_site_registry' and 'tribalcms_public_urls' in the TRIBiQ CMS global database contain this URL.
If you have access to the Global Database you should be able to do this:
mysql> use global_50
Database changed
mysql> INSERT INTO tribalcms_site_registry VALUES ('mytribiqsite','extranet-hosting.co.uk','',NULL);
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO tribalcms_public_urls SET sitename='mytribiqsite', public_url='extranet-hosting.co.uk';
Query OK, 1 row affected (0.00 sec)
Type the bits in bold and replace the parts in italics with your values.