I haven't been on MTS for a couple months and I've finally come back to get the updates for my current mods but when I try to see them through the "My Downloads" tab I get a 403 saying I'm not logged in. When I log in, it redirects me the homepage, I go to my downloads again and the same thing happens even though I was logged in. I tried accessing it on both my PC and laptop so I'm not sure if this is a MTS issue.
Make sure you remember your password, log out, clear your cookies, log back in (and use "Remember Me") and see if that helps. I'm not having any trouble with "My Downloads," so if it is a MTS issue it's not universal. It could be that the cookie got corrupted.