Access denied for Acme Automobile Reference Application (AA)

I am trying to open  Acme Automobile Reference Application (AA) in the community edition portal. But I am getting "403 - Access denied. you don't have permissions to view this page." I need this to complete the activities in Appian Community's self paced course. Any help is appreciable.

Also noticed that I got the same error for all the applications in the community edition Env. except "Community Edition Home"

 

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