Universal Login on Product Theme

Hi, I am trying to create a login area on the Product Theme/ MarketPress/ Multisite.

My domain.com/wp-login.php only works for the admin login.

If I try to login in with a different site I get this error

wp-content/plugins/wpmu-dev-seo/wds-files/wds-autolinks/wds-autolinks.php on line 287

Each site generated seems to have its own log in area so it is hard to find.

How do I create a universal login area site admins?

Thx