"An Active Directory error 0x51 occurred" error when you run the "Setup /PrepareAD" command from a DC in Exchange 2013

Symptoms

This issue occurs in a domain that has no global catalog servers. This issue occurs after you apply Cumulative Update 5 or a later version of cumulative update for Microsoft Exchange Server 2013 (Cumulative Update 6 or Cumulative Update 7). When this issue occurs, you receive the following error messages:

[Time_Point_1] [2] [ERROR] An Active Directory error 0x51 occurred when trying to check the suitability of server 'domain_controller_name'. Error: 'Active directory response: The LDAP server is unavailable.'

[Time_Point_2] [2] [ERROR] The LDAP server is unavailable.


Note This issue will not occur if you upgrade the domain controller (DC) to a global catalog.

Cause

This issue occurs because of a change that introduces DC stickiness for writable sessions into Cumulative Update 5 for Exchange Server 2013.

Resolution

To resolve this issue, install Cumulative Update 8 for Exchange Server 2013.

Need more help?

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

Was this information helpful?

Thank you for your feedback!

Thank you for your feedback! It sounds like it might be helpful to connect you to one of our Office support agents.

×