"You don't have permissions to see the task form" when trying to access the created task using the IT Orders sample

Steps here: https://www.youtube.com/watch?v=hmtuRaKlG_Y When creating the Case, try to add the wbadmin for both fields. You should see an error: "Case role 'supplier' has no matching assignments", then proceed like is told in the video and add "wbadmin"for the first user field and "admin" in the second role field.