Exchange 2013 update CU18 to CU21

Yousuf Khan
Occasional Contributor

Hi, i have just upgraded the Exchange 2013 from CU18 to CU21.


I downloaded the CU21 and run the setup file. The setup has been completed successfully however i found on one of article that before update we must prepare "Perform AD Schema and Domain Preparation for Exchange 2013 CU21" and i missed this step.


Is any one know what would be a impact and how i can fix this issue? Thank you in advance 





3 Replies

Hi @Yousuf Khan ,


When you run the setup of any CU if is necessary it will update the Schema and domain.


If you see the logs of the setup/update you will see the update of the schema if needed.

So it means i don't have to do any thing now.


Because the updates was successful and emails are working fine.


Anyway we have a hybrid setup (Office 365 and On-Premise Exchange)



Hi @Yousuf Khan,


You do not need to do nothing, but always advised to see the logs of the update at "C:\ExchangeSetupLogs\ExchangeSetup.log". 


You can read more here https://docs.microsoft.com/en-us/exchange/plan-and-deploy/install-cumulative-updates?view=exchserver... 


Regarding the hybrid, you also does not need to do nothing.

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