MarketPress not working for me

I created paid courses and am trying to test out the enrollment process (using manual payments). It seems to get stuck upon creating/logging into the account with a blank pop up. I refreshed the page and it showed me logged in. But when I went to enroll in a course, it got stock again with a blank pop up. It's also not allowing me to view my cart so that I may check out and/or or empty it.