Network Admin redirects to login form.

I am unable to access the network admin area. Anytime I try to access any part of the network admin area, it logs me out of the network completely and redirects to the login form. I put in my credentials and it just refreshes the page, essentially never logging me into the site.

Everything was working perfectly last night before I went to bed, so there have been no changes from then and now.

I deactivated all plugins that have redirection within them (via FTP), but still no change.

I’m unsure as what to do now or why this is happening to begin with. I thought that maybe my .htaccess was changed somehow, but it all looks normal to me. :/

Any advice or help would be appreciated! ??

Edit: I also turned the WP_DEBUG to ‘true’ in the wp-config.php and deactivated all plugins that had deprecated code. Still no change.