Cumulative Update 16 for Exchange Server 2016

This update also includes new daylight saving time (DST) updates for Exchange Server 2016. For more information about DST, see Daylight Saving Time Help and Support Center.

• In multidomain Active Directory forests in which Exchange is installed or has been prepared previously by using the /PrepareDomain option in Setup, this action must be completed after the /PrepareAD command for this cumulative update has been completed and the changes are replicated to all domains. Setup will try to run the /PrepareAD command during the first server installation. Installation will finish only if the user who initiated Setup has the appropriate permissions.
  
  Notes
  • If you are upgrading from Cumulative Update 13 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016 to Cumulative Update 16 for Exchange Server 2016, then there’s no need to run the /PrepareAD or /PrepareDomain. No additional actions (prepareAD, prepareDomain, or assigning permissions) are required.
  • If you have ever skipped a Cumulative Update (for example, you are upgrading from an earlier version before Cumulative Update 13 for Exchange Server 2016), or this is a first Exchange Server installation in the AD, then this Known Issue section should be taken care of.
    • About the /PrepareDomain operation in multidomain:
      
      The /PrepareDomain operation automatically runs in the Active Directory domain in which the /PrepareAD command is run. However, it may be unable to update other domains in the forest. Therefore, a domain administrator should run the /PrepareDomain in other domains in the forest.
    • About the permission question:
      
      As the /PrepareAD is triggered in Setup, if the user who initiates Setup isn't a member of Schema Admins and Enterprise Admins, the readiness check will fail and you receive the following error messages.
      
      
      
      To avoid the errors, either the user should join Schema Admins and Enterprise Admins groups or another user in Schema Admins and Enterprise Admins groups manually runs the /PrepareAD for this Cumulative Update first. Then the Exchange admin user can start Setup.
• Autodiscover Event ID 1 occurs after you install Cumulative Update 14 for Exchange Server 2016. For more information, see KB 4532190.

This cumulative update fixes the issues that are described in the following Microsoft Knowledge Base articles: 

• 4547705 Authentication loop between msft.sts.microsoft.com/adfs and OWA in Exchange Server 2016
• 4547706 Birthday isn't correctly synced to iOS native mail app in Exchange Server 2016
• 4547708 Elevation of privileges possible when Active Directory permissions role is granted in Exchange Server 2016
• 4547709 InternetWebProxyBypassList is ignored by Mailbox Replication service in Exchange Server 2016
• 4547710 New-MailboxSearch with In-Place Hold enabled replaces all values in msExchUserHoldPolicies if adding a value in Exchange Server 2016
• 4547711 Public folder permissions aren't applied from Outlook in Exchange Server 2016 hybrid environment
• 4547712 Outlook on the web (OWA) exposes junk operations even if disabled via OwaMailboxPolicy in Exchange Server 2016
• 4547713 IsOnlineMeeting is always false for Teams-only meetings in Exchange Server 2016
• 4547714 Can't add remote shared mailbox by using ECP into distribution group in Exchange Server 2016 hybrid environment
• 4547715 New created search folder retention policy is changed in Exchange Server 2016
• 4547722 Can't go from Office 365 to Enterprise in Exchange Server 2016 Exchange admin center (EAC) if Chrome SameSite Cookie is enabled
• 4547723 Can't sign in to Office 365 if configuring hybrid with Chrome SameSite Cookie enabled in Exchange Server 2016
• 4547716 Event ID 1325 and Test-ExchangeSearch crashes application pool with NullReferenceException in Exchange Server 2016
• 4536987 Description of the security update for Microsoft Exchange Server 2016: February 11, 2020
• 4540123 Description of the security update for Microsoft Exchange Server 2016: March 10, 2020

Download Center

Download Cumulative Update 16 for Exchange Server 2016 (KB4537678) now.

Download Exchange Server 2016 CU16 UM Language Packs now.

Notes

• The Cumulative Update 16 package can be used to run a new installation of Exchange Server 2016 or to upgrade an existing Exchange Server 2016 installation to Cumulative Update 16.
• You don't have to install any previously released Exchange Server 2016 cumulative updates or service packs before you install Cumulative Update 16.

Prerequisites

This cumulative update requires Microsoft .NET Framework 4.8.

A component that's used within Exchange Server requires a new Visual C++ component to be installed together with Exchange Server. This prerequisite can be downloaded at Visual C++ Redistributable Packages for Visual Studio 2013. For more information, see KB 4295081.

For more information about the prerequisites to set up Exchange Server 2016, see Exchange 2016 prerequisites.

Restart requirement

You may have to restart the computer after you apply this cumulative update package.

Registry information

You don't have to make any changes to the registry after you apply this cumulative update package.

Removal information

After you install this cumulative update package, you can't uninstall the package to revert to an earlier version of Exchange Server 2016. If you uninstall this cumulative update package, Exchange Server 2016 is removed from the server.

File hash information

For more information about the deployment of Exchange Server 2016, see Release notes for Exchange 2016.

For more information about the coexistence of Exchange Server 2016 and earlier versions of Exchange Server in the same environment, see Exchange 2016 system requirements.

For more information about other Exchange updates, see Exchange Server Updates: Build numbers and release dates.

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