Please share with us the lesson, just as Alahakoon did and we will fix it for you.
Unfortunately there are some known issue with the system and sometimes these links get broken. We have fixed it on the pre-production system, hopefully tonight everything will be working in production too. Until then please use the following documents for your exercises:
Hi: I am having the same problem. The exercise files you posted are great but they don't fully solve the problem . . . also need the .jar files. I can't do the exercises without the .jar files
Class: Decision Management Advanced (7.1)
Lesson: 2 - Decision Manager Portal Overview (Practicing What You Learned)
Issue: Unable to download the files. I receive a pop up error message from academy.pega.com: " Unable to open attachment. You lack the required permissions."
[Note: Unable to insert any images into this post. The insert image function does not have access to a local browse (or I am being blind). It only has a Browse Server button; which seems to browse the PDN server]