Ad upgrade

Hi All,

We have three domain controllers (1 - Server 2008 R2 and 2 - Server 2008). Our domain and Forest levels are Server 2008.

We are in the process of introducing Server 2016 as domain controller. When I run adprep /Forestprep from server 2016 iso on our PDC Server 2008 R2, I keep getting the following error. I have added my account to Enterprise and Schema admins groups. Has anyone come across this issue?

Adprep detected that the supplied or default user is not a member of the followi
ng group: Enterprise Admins group and Schema Admins group.
[Status/Consequence]
Adprep has stopped without making changes.
[User Action]
Verify the user is a member of Enterprise Admins group and Schema Admins group.