I'm enrolled in the System Architect 7.2 course and have run across this exact same error message in Lesson 8: Process Design, Section: Configuring a Work Party, Exercise: Test Step #3. See attached screen print.
I'm a Pega newbie, so I'm in need of assistance with this issue, thanks in advance.
I figured out my issue. I must have done the exercise steps out of sequence, or saved them out of sequence. Once I checkout, saved and checkedin the WorkParty again, my new Onboarding Case passed the Test step. Thought I'd let others know in case they run into the same issue.