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.

Need more help?

Expand your skills
Explore Training
Get new features first
Join Microsoft Insiders

Was this information helpful?

What affected your experience?

Thank you for your feedback!

×