Following the link from "New UX Design Course" under documentation takes you to a login screen for Appian employees. If the course is employee only don't publicize it in the public site.
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Hello. I'm so sorry for the wrong link, but thank you so much for bringing it to our attention! Here is the correct link to the UX course: https://academy.appian.com/#/online-courses/51361f70-8984-4a70-9ff8-0180cfb9d718. You can also navigate there by going to academy.appian.com and searching for the course name "UX Design and Appian."
We'll get that link fixed in the docs as soon as possible. Thanks again for letting us know!
Kara