The login form isn'r rendered
You are going to need to open phpmyadmin from your hosting, and look in the &quot;block&quot; table.

Look for the &quot;main&quot; block, and edit the status to &quot;1&quot; and the region to &quot;content&quot; (or whatever your main region is defined as in your themes .info file).
It seems strange that disabling the main content block would hide the login form though, I thought they were separate.