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Exchange 2019 CU6 Released

Exchange 2019 CU6 has been released to the Microsoft Volume Licensing Center!  Exchange 2019 has a different servicing strategy than Exchange 2007/2010 and utilises Cumulative Updates (CUs) rather than the Rollup Updates (RU/UR) which were used previously.    CUs are a complete installation of Exchange 2019 and can be used to install a fresh server or to update a previously installed one. Exchange 2013 and 2016 have the same servicing methodology.

Volume Licensing Download Site

Details for the release are contained in KB 4556415.

Updates Of Particular Note

Pipelining support was added to the Restore-RecoverableItems cmdlet to ease administration tasks.

4547707 Enable piping for Restore-RecoverableItems in Exchange Server 2019

The Security posture of OWA was updated as per KB 4559446 Changes to Outlook on the web blocked file extensions and MIME types in Exchange Server 2016

The list below is the file extensions noted as of 16-6-2020:

  • .appref-ms – Windows ClickOnce
  • .cdxml – PowerShell cmdlet definition
  • .pssc – PowerShell session configuration
  • .udl – Microsoft Data Link, used by Microsoft Data Access Components (MDAC)
  • .wsb – Windows sandbox
  • .vhd
  • .vhdx
  • .py
  • .pyc
  • .pyo
  • .pyw
  • .pyz
  • .pyzw

Note that there are some known issues which are discussed in the release KB.  For net new Exchange installations there are additional operations required for multiple domain environments where /PrepareAD needs to be executed manually in the other domains.

This CU still has the Autodiscover EventID 1 error in the Application event log.  See KB 4532190 for details.

 

Please note  that .NET Framework 4.8 is a requirement.  See this post if installing .NET and the Exchange CU in the same maintenance window.

Details are listed in the Exchange Server prerequisites.  Also note the requirement for Visual C++ Redistributable Package for Visual Studio 2012.

Note that an Exchange 2019 install requires Windows Server 2019.  This is documented in the Exchange Support Matrix.

Issues Resolved

  • 4559441 Foreign language characters set in RejectMessageReasonText of a transport rule aren’t shown correctly in Exchange Server 2019
  • 4547707 Enable piping for Restore-RecoverableItems in Exchange Server 2019
  • 4549689 HMA EvoSTS certificate rollover causes authentication prompts due to stalled key on worker process spawn (warmup phase) in Exchange Server 2019
  • 4559446 Changes to Outlook on the web blocked file extensions and MIME types in Exchange Server 2019
  • 4559440 Export to a PST for an eDiscovery search fails Exchange Server 2019
  • 4559439 EAS creates failure report if a message with unknown recipients is in Drafts in Exchange Server 2019
  • 4559442 2080 Events caused by empty values in HKLM\SYSTEM\CurrentControlSet\Services\MSExchange ADAccess\Instance0 in Exchange Server 2019
  • 4559438 Edge Transport server hangs in Exchange Server 2019
  • 4559443 Managed Folder Assistant fails with Event ID 9004 NotInBagPropertyErrorException in Exchange Server 2019
  • 4559437 PR_RECIPIENT_ENTRYID is computed if no email address or type in Exchange Server 2019
  • 4559444 Conversion from HTML to RTF removes non-breaking space in Exchange Server 2019
  • 4559436 Attachments with properties (like Azure Information Protection labels) not always matching in Exchange Server 2019
  • 4559435 Introduce an OrganizationConfig flag to enable or disable recipient read session in Exchange Server 2019

Some Items For Consideration

Exchange 2019 follows the same servicing paradigm for Exchange 2013 and 2016 which was previously discussed on the blog.  The CU package can be used to perform a new installation, or to upgrade an existing Exchange Server 2019 installation to this CU.  Cumulative Updates are well, cumulative.  What else can I say…

Customers with a hybrid Exchange deployment, must keep their on-premises Exchange servers updated to the latest update or the one immediately prior ( N or N-1).

  • Test the CU in a lab which is representative of your environment
  • Review this post to also factor in AD preparation which is to be done ahead of installing the CU onto the first Exchange server
  • Follow your organisation’s change management process, and factor the approval time into your change request
  • Provide appropriate notifications as per your process.  This may be to IT teams, or to end users.
  • After you install this cumulative update package, you cannot uninstall the cumulative update package to revert to an earlier version of Exchange. If you uninstall this cumulative update package, Exchange is removed from the server.
  • Place the server into SCOM maintenance mode prior to installing, confirm the install then take the server out of maintenance mode
  • Place the server into Exchange maintenance mode prior to installing, confirm the install then take the server out of maintenance mode
  • I personally like to restart prior to installing CUs.  This helps identifies if an issue was due to the CU or happened in this prior restart, and also completes any pending file rename operations.  3rd party AV products are often guilty of this
  • Restart the server after installing the CU
  • Ensure that all the relevant services are running
  • Ensure that event logs are clean, with no errors
  • Ensure that you consult with all 3rd party vendors which exist as part of your messaging environment.  This includes archive, backup, mobility and management services.
  • Ensure that you do not forget to install this update on management servers, jump servers/workstations and application servers where the management tools were installed for an application.  FIM and 3rd party user provisioning solutions are examples of the latter.
  • Ensure that the Windows PowerShell Script Execution Policy is set to “Unrestricted” on the server being upgraded or installed.  See this article on setting PowerShell to Unrestricted.
  • Disable file system antivirus prior to installing. Do this through the appropriate console.  Typically this will be a central admin console, not the local machine.
  • Verify file system antivirus is actually disabled
  • Once server has been restarted, re-enable file system antivirus.

Please enjoy the update responsibly!

What do I mean by that?  Well, you need to ensure that you are fully informed about the caveats with the CU  and are aware of all of the changes that it will make within your environment.  Additionally you will need to test the CU your lab which is representative of your production environment.

Cheers,

Rhoderick

Rhoderick Milne [MSFT]

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