Hi all - the GDATF has some technical issues this week, and I just had a problem logging in.
I was able to resolve it by clearing my browsing history and restarting the computer.
Instructions for doing this vary by browser (Chrome, Safari, Internet Explorer, Firefox, etc.), but you can Google "clear browsing history "
If you are still having difficulty, you can report login issues here:http://gdatf.org/about/contact/technical-support/