Cannot Log Into Site

I cannot log into my site. I have the correct credentials. When I log in it acts like it is going to log in but just reverts to the log in page – with no error. I do receive an e-mail from my security plug-in notifying me that I am logging in but not the case. I tried logging in with a secondary credential with the same result. I tried creating a new log-in and it does not send the e-mail to setup the password. I tried disabling my plug-ins but no change. I tried removing my .htaccess file from the root, but no change. I restored my web site from yesterdays backup but nothing. I was able to log in this morning but now nothing.

The page I need help with: [log in to see the link]