Unable to sign in, work tracking not working and course work not saving

Good afternoon, I have been working through the course that you have laid out, there has been a change today, at present I am unable to log in to continue the course, the tracking for the course work is not tracking from today only since not able to log on, as well as the little green squares mapping out your time working the course, is not logging in my time shades of green since I restarted the course, about a month ago.

Please can you help