This cumulative update includes fixes for nonsecurity issues and all previously released fixes for security and nonsecurity issues.
Known issues in this cumulative update
- 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.
- If you are upgrading from Cumulative Update 13 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016 to Cumulative Update 17 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.
- About the /PrepareDomain operation in multidomain:
- Autodiscover Event ID 1 occurs after you install Cumulative Update 14 for Exchange Server 2016. For more information, see KB 4532190.
Issues that this cumulative update fixes
- 4559444 Conversion from HTML to RTF removes non-breaking space in Exchange Server 2016
- 4559435 Introduce an OrganizationConfig flag to enable or disable recipient read session in Exchange Server 2016
- 4547707 Enable piping for Restore-RecoverableItems in Exchange Server 2019 and 2016
- 4559436 Attachments with properties (like Azure Information Protection labels) don’t always match in Exchange Server 2016
- 4559437 PR_RECIPIENT_ENTRYID is computed if no email address or type in Exchange Server 2016
- 4559438 Edge Transport server hangs in Exchange Server 2016
- 4559439 EAS creates failure report if a message with unknown recipients is in Drafts in Exchange Server 2016
- 4559440 Export to a PST for an eDiscovery search fails in Exchange Server 2016
- 4559441 Foreign language characters set in RejectMessageReasonText of a transport rule aren’t shown correctly in Exchange Server 2016
- 4559442 2080 Events caused by empty values in HKLM\SYSTEM\CurrentControlSet\Services\MSExchange ADAccess\Instance0 in Exchange Server 2016
- 4549689 HMA EvoSTS certificate rollover causes authentication prompts due to stalled key on worker process spawn (warmup phase) in Exchange Server 2016
- 4559443 Managed Folder Assistant fails with Event ID 9004 NotInBagPropertyErrorException in Exchange Server 2016
- 4559446 Changes to Outlook on the web blocked file extensions and MIME types in Exchange Server 2016