Hi Sanjay,
I understand your explanation, but I do not see how it explains the problem I am having.
In this case, I am logged in with the default Administrator Access Profile, meaning the “Administrative Permissions” checkbox is checked. In other words, I have all permissions.
I am trying to change a person who’s Access Profile is also the default Administrator Access Profile to the default Regular User Access Profile.
As an Administrator Access Profile, I have all permissions. Therefore, I cannot see any reason why I could not change a user to the Regular User Access Profile.