Emerging Issues for Exchange On-Premises
This page lists emerging issues for Exchange On-Premises deployments, possible root cause and solution/workaround to fix the issues. The page will be consistently updated with new issues found and reflect current status of the issues mentioned.
Current Issues
8/18/2025 — Rich hybrid features temporarily unavailable after deploying dedicated Exchange hybrid app
Update causing the issue: Dedicated Exchange hybrid app created using ConfigureExchangeHybridApplication script or the HCW method
Issue: After deploying dedicated Exchange hybrid app using HCW or the ConfigureExchangeHybridApplication script you may notice Rich hybrid features i.e. Free/Busy, MailTips and Photos temporarily unavailable.
Workaround/Solution: Depending on the size of the organization, it may take up to 60 minutes for the dedicated Exchange hybrid application configuration to be recognized by the responsible Exchange Server processes. The process can be expedited by performing IISReset or recycling MSExchangeServicesAppPool on Exchange Servers. Please check this documentation for details.
2/24/2025 — Outlook connectivity issues with SSL offloading after CU14/CU15
Update causing the issue: Exchange Server 2019 CU14 OR Exchange Server 2019 Cumulative Update 15
Issue: Environments that are using SSL offloading configuration may face Outlook connectivity issues after upgrading to Exchange Server 2019 CU14 OR Exchange Server 2019 Cumulative Update 15.
Workaround/Solution: As announced in August 2023, by default, starting with Exchange Server 2019 CU14, setup enables the Windows Extended Protection (EP) feature on the Exchange server being installed. Extended Protection isn't supported in environments that use SSL Offloading. SSL termination during SSL Offloading causes Extended Protection to fail. To enable Extended Protection in your Exchange environment, you must not be using SSL offloading with your Load Balancers. Please check this link for more details.
2/6/2025 — Migration Endpoint creation fails via HCW
Update causing the issue: HCW
Issue: You may see the following error when creating Migration Endpoint using HCW:
The last connection attempt happened too recently
Workaround/Solution: Please create the Migration Endpoint manually by following steps in this article while the issue is being fixed in HCW.
1/29/2025 — Error 1935 when installing November 2024 V2 Exchange Security Update
Update causing the issue: November Exchange Security Update for Exchange 2016 & Exchange 2019 V2
Issue: You may see the following error when installing November 2024 V2 Exchange Security Update:
Error 1935. An error occurred during the installation of assembly 'Microsoft.Exchange.Data.Common,version="15.1.2503.00",fileVersion="15.1.2507.44",culture="neutral",publicKeyToken="31BF3856AD364E35",processorArchitecture="MSIL"'.
HRESULT: 0x800700B7. assembly interface: IAssemblyCacheItem, function: Commit, component: {B79F9EB4-6D81-48F3-BC2D-3A0A83C30742}
Workaround/Solution: Please follow the workaround provided on this KB article.
Old Issues
11/29/2024 — Time zone exception after installing November 2024 SU V2
Update causing the issue: November Exchange Security Update for Exchange 2016 & Exchange 2019 V2
Issue: Time zone exception may be reported in event viewer, after installing the November Exchange Security Update for Exchange 2016 & Exchange 2019 V2.
Event log entries are generated if Exchange Server fails to process calendar information, such as:
w3wp#MSExchangeOWAAppPool, M.Exchange.Net, M.E.E.ExIanaTimeZoneProvider+Cache.AddTimeZone, M.E.ExchangeSystem.InvalidTimeZoneException
Microsoft.Exchange.ExchangeSystem.InvalidTimeZoneException: Time zone id already exists
Workaround/Solution: Please follow the workaround provided on this KB article.
11/27/2024 — Transport Rules stop working after November 2024 SU
Update causing the issue: November Exchange Security Update for Exchange 2016 & Exchange 2019
Issue: Exchange Transport Rules may stop working after applying the November Exchange Security Update for Exchange 2016 & Exchange 2019.
Workaround/Solution: Please install the re-released November 2024 Exchange security update.
9/11/2024 — Transport service crashing or Filtering Management Service delayed after August 2024 Windows Update
Update causing the issue: August 2024 update for Windows
Issue: After installing the August 2024 update for Windows:
- Microsoft Exchange Transport service may start crashing
- Microsoft Filtering Management Service may not start or start with long delay
Workaround/Solution: Update on 9/11/2024 — Install Windows Update for September 2024 or later.
~~Please follow steps in this KB~~
4/23/2024 — Search in Outlook fails after March 2024 SU
Update causing the issue: March 2024 Security Update for Exchange 2019,2016
Issue: After installing the March 2024 Security Update,
Search in Outlook (cached mode) may show
We're having trouble fetching results from the server....
The search works fine in OWA or Outlook online mode.
Workaround/Solution: Please install April 2024 Hotfix Update.
4/23/2024 — Add-ins stop working after March 2024 SU
Update causing the issue: March 2024 Security Update for Exchange 2019,2016
Issue: After installing the Security Update, add-ins may stop working with following error:
Add-in Error Something went wrong and we couldn't start this add-in. Please try again later or contact your system administrator
Workaround/Solution: Please install April 2024 Hotfix Update.
4/23/2024 — Unread envelope icon not updating after March 2024 SU
Update causing the issue: March 2024 Security Update for Exchange 2019,2016
Issue: After installing the March 2024 Security Update, Unread envelope icon is not getting updated.
Workaround/Solution: Please install April 2024 Hotfix Update.
4/23/2024 — Office document preview fails in OWA after March 2024 SU
Update causing the issue: March 2024 Security Update for Exchange 2019,2016
Issue: After installing the March 2024 Security Update, preview of Office documents in OWA may fail with error:
Sorry, there was a problem and we can't open this document.
Workaround/Solution: Please install April 2024 Hotfix Update.
2/19/2024 — CU14 RecoverServer fails creating PushNotificationsVirtualDirectory
Update causing the issue: CU 14 for Exchange 2019
Issue: Exchange 2019 CU14 RecoverServer fails while creating "New-PushNotificationsVirtualDirectory" with following error:
Exception setting "ExtendedProtectionTokenChecking": "Cannot convert null to type "Microsoft.Exchange.Data.Directory.SystemConfiguration.ExtendedProtectionTokenCheckingMode" due to enumeration values that are not valid.
Workaround/Solution: Please follow the steps from this KB to resolve the issue.
11/23/2023 — Queue viewer crashing after November 2023 SU
Update causing the issue: November 2023 Security Update for Exchange 2016, Exchange 2019
Issue: Some customers may find queue viewer crashing with error:
Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints
Workaround/Solution: The error can occur if the Exchange server auth certificate has expired. Solution is to renew the Exchange server auth certificate manually or by using this script.
10/12/2023 — Account forest users can't change expired password in OWA after August 2023 SU
Update causing the issue: All versions of August 2023 Security Update for Exchange 2016, Exchange 2019
Issue: Users in account forest can't change expired password in OWA in multi-forest Exchange deployments after installing any version of August 2023 Security Update for Exchange servers.
Note: The account forest user will be able to change the password after they sign in to Outlook on the web if their password is not yet expired. The issue affects only account forest users who have passwords that are already expired. This change does not affect users in organizations that don't use multiple forests.
Workaround/Solution: Update on 10/12/2023 — Follow steps on this article.
8/15/2023 — Non-English August 2023 SU installation fails
Update causing the issue: Non-English August 2023 Security Update for Exchange 2016, Exchange 2019
Issue: When you install the Microsoft Exchange Server 2019 or 2016 August 2023 Security Update (SU) on a Windows Server-based device that is running a non-English operating system (OS) version, Setup suddenly stops and rolls back the changes. However, the Exchange Server services remain in a disabled state.
Workaround/Solution: The latest SUs have been released that do not require a workaround to install. If you used a workaround to install KB5029388, it is highly recommended to uninstall the KB5029388 to avoid issues down the line. For more information please check out this KB.
6/15/2023 — Exchange uninstall fails after January 2023 SU
Update causing the issue: January 2023 Security Update for Exchange 2016, Exchange 2019
Issue: When you try to uninstall Microsoft Exchange Server 2019 or 2016 on servers that had January 2023 Security Update for Exchange Server installed at any point, the Setup fails with the following error message:
[ERROR] The operation couldn't be performed because object '<ServerName>' couldn't be found on '<DomainControllerName>'.
Workaround/Solution: Install Exchange Security Update June 2023 or higher to resolve the issue. Check this KB for more details.
6/15/2023 — Public Folder permissions can't be changed with Extended Protection enabled
Update causing the issue: Extended protection enabled on Exchange server
Issue: Changing the permissions for Public Folders by using an Outlook client will fail with the following error, if Extended Protection is enabled:
The modified Permissions cannot be changed.
Workaround/Solution: Install the Exchange Server June 2023 or higher Security Update and create the setting override mentioned in this KB.
3/16/2023 — Outlook client update for CVE-2023-23397
Update causing the issue: Outlook client update for CVE-2023-23397 released
Issue: These vulnerabilities affect Exchange Server. Exchange Online customers are already protected from the vulnerabilities addressed in these SUs and do not need to take any action other than updating Exchange servers in their environment, and if applicable, installing the security update for Outlook on Windows described on the link on the right.
More details about specific CVEs can be found in the Security Update Guide (filter on Exchange Server under Product Family).
Awareness: Outlook client update for CVE-2023-23397 released
There is a critical security update for Microsoft Outlook for Windows that is required to address CVE-2023-23397. To address this CVE, you must install the Outlook security update, regardless of where your mail is hosted (e.g., Exchange Online, Exchange Server, some other platform).
Workaround/Solution: Please check this page for FAQs about the Outlook CVE-2023-23397.