The Exchange Team released the quarterly Cumulative Updates for Exchange Server 2019 as well as Exchange 2016. Like the previous two Cumulative Updates, these require .NET Framework 4.8.
Apart from fixes as well as security updates included from the previous CU, these update contain the following changes for both builds:
- Added additional file types to default OWA Mailbox Policy for Blocked File Extensions. More information in KB4559446.
- Added support to Restore-RecoverableItems for easier usage. More details in KB4547707.
Links to the updates as well as a description of changes and fixes are described below.
| Version | Build | KB | Download | UMLP | Schema |
| Exchange 2019 CU6 | 15.2.659.4 | KB4556415 | VLSC | N | |
| Exchange 2016 CU17 | 15.1.2044.4 | KB4556414 | Download | UMLP | N |
Exchange 2019 CU6 fixes:
- 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
Exchange 2016 CU17 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
Notes:
- These Cumulative Updates do not contain schema changes compared to their previous Cumulative Update.
- When upgrading from an n-2 or earlier version of Exchange, or an early version of the .NET Framework, consult Upgrade Paths for CU’s & .NET.
- Don’t forget to put the Exchange server in maintenance mode prior to updating. Regardless, setup will put the server in server-wide offline mode post-analysis, before making actual changes.
- When using Exchange hybrid deployments or Exchange Online Archiving (EOA), you are required to delay installing at most one version (n-1).
- If you want to speed up the update process for systems without internet access, you can follow the procedure described here to disable publisher’s certificate revocation checking.
- Cumulative Updates can be installed directly; no need to install RTM prior to installing Cumulative Updates.
- Once installed, you can’t uninstall a Cumulative Update nor any of the installed Exchange server roles.
- The order of installation shouldn’t matter with the “every server is an island” concept, yet recommended is to upgrade internet-facing, non-internet-facing servers first, followed by Edge Transports.
Caution:
As for any update, I recommend to thoroughly test updates in a test environment prior to implementing them in production. When you lack such facilities, hold out a few days and monitor the comments on the original publication or forums for any issues.
EighTwOne (821) 