Exchange 2013 CU15 Released

Exchange 2013 CU15 has been released to the Microsoft download centre!  Exchange 2013 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 2013 and can be used to install a fresh server or to update a previously installed one.  Exchange 2013 SP1 was in effect CU4, and CU15 is the eleventh post SP1 release.  How time flies…..

Exchange 2013 CU15 Download

This is build 15.00.1263.005 of Exchange 2013 and the update is helpfully named Exchange2013-x64-cu15.exe.  Which is a great improvement over the initial CUs that all had the same file name!  Details for the release are contained in KB 3197044.

Whether or not your AD Schema needs to be updated depends upon your initial Exchange 2013 version.  This will dictate if the AD Schema needs to be modified.  Check the values as noted in this post.  There may be additional RBAC definitions, so PrepareAD should be executed prior to installing CU15.  If setup detects that PrepareAD is required it will be automatically executed if the account running setup has the necessary permissions.  This was an issue first discussed in the MessageCopyForSentAsEnabled  post.


Updates Of Particular Note

CU15 contains the latest time zone updates.

The fix for the recent public folder indexing issues is included with CU15.  This was an issue introduced in both Exchange 2013 CU14 and Exchange 2016 CU3.  This is discussed in KB 3202691 - Public folders indexing doesn't work correctly after you apply latest cumulative updates for Exchange ServerNote After you install this update on either version of Exchange Server, you should move the public folder mailbox to a new database to make sure that all items are indexed correctly.

CU15 supports .NET framework 4.6.2 – while this is an optional upgrade at this time, it makes sense to plan the .NET upgrade as it will become a required pre-requisite for the next CU.

On net-new installs the Desktop Experience feature is no longer required, since Windows has refactored how the components are installed in the newer versions of Windows.  This allows net-new installs of Exchange 2013 CU15 and Exchange 2016 CU4 to install less components than before as only the Media Foundation feature will be installed when using the /InstallWindowsComponents setup switch.  Since this is for net-new installs, upgrades to existing servers using either of the two aforementioned CUs will not change the installed OS components.  If you desire, you can add Media Foundation and remove the desktop experience after installing these CUs. This is optional.


Issues Resolved

KB 3198092 Update optimizes how HTML tags in an email message are evaluated in an Exchange Server 2013 environment

KB 3189547 FIX: Event ID 4999 for a System.FormatException error is logged in an Exchange Server 2013 environment

KB 3198046 FIX: The UM mailbox policy is not honored when UM call answering rules setting is set to False in an Exchange Server 2013 environment

KB 3195995 FIX: Event ID 4999 with MSExchangerepl.exe crash in Exchange Server 2013

KB 3208886 Send As permission of a linked mailbox is granted to a user in the wrong forest in Exchange Server 2013

KB 3188315 Messages are stuck in outbox when additional mailboxes are configured in Outlook on Exchange Server 2013

KB 3202691 Public folders indexing doesn't work correctly after you apply latest cumulative updates for Exchange Server

KB 3203039 PostalAddressIndex property isn't returning the correct value in Exchange Server 2013

KB 3198043 Shadow OAB downloads don't complete in Exchange Server 2013

KB 3208885 Microsoft.Exchange.Store.Worker.exe process crashes after mailbox is disabled in Exchange Server 2013

KB 3201966 MSExchangeOWAAppPool application pool consumes excessive memory on restart in Exchange Server 2013

KB 3209041 FIX: An ActiveSync device becomes unresponsive until the sync process is complete in an Exchange Server environment

KB 3209013 FIX: The LegacyDN of a user is displayed incorrectly in the From field in the Sent Items folder on an ActiveSync device

KB 3209018 FIX: Results exported through the eDiscovery PST Export Tool never finishes in an Exchange Server environment

KB 3199519 Inconsistent search results when email body contains both English and non-English characters in Exchange Server 2013

KB 3211326 "ConversionFailedException" error when emails are sent on the hour in Exchange Server 2013


Some Items For Consideration

As with previous CUs, this one also follows the new servicing paradigm 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 2013 installation.  You do not need to install Cumulative Update 4 or 5 for Exchange Server 2013 when you are installing the latest CU.  Cumulative Updates are well, cumulative.  What else can I say…

  • After you install this cumulative update package, you cannot uninstall the cumulative update package to revert to an earlier version of Exchange 2013. If you uninstall this cumulative update package, Exchange 2013 is removed from the server.
  • Place the server into maintenance mode prior to installing, confirm the install then take the server out of maintenance mode
  • Restart the server after installing the CU
  • 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 KB981474.
  • Disable file system antivirus prior to installing.
  • Once server has been restarted, re-enable file system antivirus.
  • Note that customised configuration files are overwritten on installation.  Make sure you have any changes fully documented!
  • While CU15 does not add any new AD Schema changes, if you are on an out-dated CU currently then deploying CU15 may contain AD Schema updates for your organisation – please test and plan accordingly!  Whether or not your AD Schema needs to be updated depends upon your initial Exchange 2013 version.  This will dictate if the AD Schema needs to be modified.  Check the values as noted in this post.  Additional RBAC definitions may also be required.

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.



Rhoderick Milne [MSFT]

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