This is a frustrating issue to come across when trying to roll out AD Schema Updates during an Exchange Cumulative Upgrade. But luckily it’s normally quite simple to resolve, this article will cover the various solutions from most to least likely to fix the issue.

The Solution

1. Verify the user account that is currently logged into the Exchange server.
2. Verify that the account is in both the Enterprise Admins group and the Schema Admins group in Active Directory.
3. Verify that the user’s Primary group is set to Enterprise Admins.
4. Ensure that the domain has had sufficient time to synchronise permission changes.
5. Sign out completely of the server where the upgrade is being performed.
6. Sign back in to the Exchange server.
7. Ensure that Command Prompt is ran as administrator and the installer should now work as expected.

Note: Do not use PowerShell to launch the setup.