Can you please confirm that the exercises you are referring to are the exercises from the Pega Decision Management Essentials (7.1) course and the exercise system (VM) you are using is the one downloaded from this course?
Please note that the two Essentials courses, i.e.:
a) Pega Decision Management Essentials (7.1) and
b) Pega Marketing Essentials (7.1)
have their own respective VMs. You cannot complete exercises from one course on a VM downloaded from the other course.
Just trying to login to a separate VM on the version I upgraded but I can't find the Pega Decision Management Essentials (7.1) VM login details anywhere? The quick start guide only gives the one for design studio login which I believe is unique to the Pega Marketing Essentials course?