Hi @Anonymous ,
Thanks for reaching out.
I understand you are trying to delete all the role assignments to Privileged Role Administrator and getting error while deleting last assignment.
The error you are getting is expected as you can't remove last assignment from Privileged Role Administrator. This role manages Azure AD PIM and grants the ability to manage assignments for all Azure AD roles including the Global Administrator role.
The Azure AD Privileged Identity Management (PIM) service also allows Privileged role administrators to make permanent admin role assignments.
This has only been setup like that only for Privileged Role Administrator, not for all the administrator roles.
Hope this will help.
Thanks,
Shweta
-----------------------------------
Please remember to "Accept Answer" if answer helped you.