This cumulative update is a security update. It 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 2 for Exchange Server 2019 to Cumulative Update 3 for Exchange Server 2019, then there’s no need to run the /PrepareAD or /PrepareDomain. No additional actions (prepareAD, prepareDomain, or assigning permissions) are required.
- If you has ever skipped a Cumulative Update (for example, you are upgrading from an earlier version before Cumulative Update 2 for Exchange Server 2019), or this is a first Exchange Server installation in the AD, then this Known Issue section should be taken care of.
a. About the /PrepareDomain operation in multidomain:
The /PrepareDomain operation automatically runs in the Active Directory domain in which the /PrepareAD commandis 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.
b. 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 error messages, 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.
- The Set-SendConnector cmdlet does not work for Exchange Server 2019 in hybrid scenarios that have a Edge server installed. For more information, see KB 4523519.
- Autodiscover Event ID 1 after installing Cumulative Update 3 for Exchange Server 2019. For more information, see KB 4532190.
Issues that this cumulative update fixes
This cumulative update also fixes the issues that are described in the following Microsoft Knowledge Base articles:
- 4515257 Hash mismatch is reported for Exchange DLLs in the bin directory of Exchange Server 2019
- 4513500 Can’t sign in to OWA or EAC after you install Exchange Server 2019 CU2 with AD FS
- 4502159 Adding or removing mailbox permission in EAC doesn’t address the msExchDelegateListLink attribute in Exchange Server 2019 and 2016
- 4515276 Room mailbox accepts a meeting as “Free” if a booking delegate is set in Exchange Server 2019 and 2016
- 4515275 Enable Get/Restore-RecoverableItems to work with Purges folder in Exchange Server 2019 and 2016
- 4515274 AutodiscoverV2 request returns REST API endpoint not AutoDiscoverV1 endpoint in Exchange Server 2019 and 2016
- 4515269 SentToMemberOf shows every recipient type not distribution groups when you create transport rule in Exchange Server 2019 and 2016
- 4515272 Message is blocked in “SMTP Delivery to Mailbox” queue if exchange server is added in groups of a child domain in Exchange Server 2019 and 2016
- 4515271 Can’t convert a migrated remote user mailbox to shared in Exchange Server 2019 and 2016
- 4515270 SubmissionQueueLengthMonitor shows “System.ArgumentException: Transition timeout…” in Exchange Server 2019 and 2016
- 4515267 NDR occurs when you resend message from alternate journaling mailbox to journaling mailbox in Exchange Server 2019 and 2016
- 4515265 Removing In-Place Hold doesn’t work for mailboxes in different domains in Exchange Server 2019 and 2016
- 4515264 FindPeople request from Skype for Business on Mac fails with “Invalid Shape Specification” in Exchange Server 2019 and 2016
- 4515263 Hide the “Validate-MailFlowThroughFrontDoor” command for Exchange Server 2019 and 2016
- 4515262 Enable Remove-MobileDevice to delete mobile devices after migrating to Office 365 from Exchange Server 2019 and 2016
- 4515261 Can’t copy eDiscovery search results for mailboxes with Exchange online archives in Office 365 in Exchange Server 2019 and 2016
- 4515273 Mailbox auditing fails when using SHA1Managed in Exchange Server 2019 and 2016
- 4515266 Infinite loop in Recurrence.GetNumberOfYearsBetween() with the Japanese calendar in Exchange Server 2019 and 2016
- 4520319 S/MIME signed reply draft behaves like the first message in conversation in Exchange Server 2019 and 2016
- 4515832 Description of the security update for Microsoft Exchange Server 2019 and 2016: September 10, 2019