I just tried to log in as usual. When I clicked on "Login" I got an unfamiliar login box. I filled in my information and hit "Log In", but it just closed the box and left me on the same page instead of going to the "exercises" page. I tried repeatedly in three different browsers with the same result. However, when I came to this page directly I found I was logged in, and I can go from here to the exercises page as normal.