It appears that logging in does not currently work. I keep getting either the "Unable to continue login. Your session most likely timed out." or the "There seems to be a problem with your login session; this action has been canceled as a precaution against session hijacking. Please resubmit the form." message every time I try to log in. Also, when I try to save an edit, the "loss of session data" error message appears.
Please fix this ASAP.