Symptoms

When you run PrepareAD in Microsoft Exchange Server 2019 or 2016 to set up an Active Director forest, Setup fails if either of the following conditions is true:

  • The Computers container is renamed or moved.

  • The read-only domain controllers (RODC) are renamed or moved to different organizational units (OU).

Additionally, the process generates the following error message: 

System.NullReferenceException: Object reference not set to an instance of an object

Resolution

To fix this issue, install one of the following updates:

Cumulative Update 11 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019

Cumulative Update 22 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016

References

Learn about the terminology that Microsoft uses to describe software updates.

References

Learn about the terminology that Microsoft uses to describe software updates.

Facebook LinkedIn Email
SUBSCRIBE RSS FEEDS

Need more help?

Want more options?

Discover Community

Explore subscription benefits, browse training courses, learn how to secure your device, and more.

Microsoft 365 subscription benefits

Microsoft 365 training

Microsoft security

Accessibility center

Communities help you ask and answer questions, give feedback, and hear from experts with rich knowledge.

Ask the Microsoft Community

Microsoft Tech Community

Windows Insiders

Microsoft 365 Insiders