This could be a caching issue in Google Chrome, please do the following:

•             Log out of all Pega sessions

•             Close all browser tabs/windows

•             Completely clear browser cache and cookies

•             Restart browser and retry access via academy.pega.com

•             If issue persist try incognito mode or/and different browser

Please let me know if this resolves your issue,

Sean

Pega Academy Self Study Support Team