diff --git a/docs/Emerging-Issues.md b/docs/Emerging-Issues.md index ac32ffa88f..2aafead0cd 100644 --- a/docs/Emerging-Issues.md +++ b/docs/Emerging-Issues.md @@ -7,26 +7,26 @@ hide: 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. -|**Updated on** | **Update causing the issue**| **Issue**| **Workaround/Solution** +|**Updated on**|**Update causing the issue**|**Issue**|**Workaround/Solution**| |-|-|-|-| -3/14/2024 | [March 2024 Security Update for Exchange 2019,2016](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-march-2024-exchange-server-security-updates/ba-p/4075348) | After installing the [March 2024 Security Update]((https://techcommunity.microsoft.com/t5/exchange-team-blog/released-march-2024-exchange-server-security-updates/ba-p/4075348)), 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. | Use one of the following workarounds:
1) Use OWA or Outlook online mode for search
2) Disable server assisted search by creating following registry key:
Path: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Search • Value name: DisableServerAssistedSearch • Value type: REG_DWORD • Value: 1 -2/20/2024 | [CU 14 for Exchange 2019](https://support.microsoft.com/KB/5035606) | Environments that are using SSL offloading configuration may face issues with Outlook connectivity issues after upgrading to Exchange 2019 CU14. | As announced in [August 2023](https://techcommunity.microsoft.com/t5/exchange-team-blog/coming-soon-enabling-extended-protection-on-exchange-server-by/ba-p/3911849) , by default, starting with 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](https://learn.microsoft.com/exchange/plan-and-deploy/post-installation-tasks/security-best-practices/exchange-extended-protection?view=exchserver-2019#scenarios-that-could-affect-client-connectivity-when-extended-protection-was-enabled) for more details -2/20/2024 | [CU 14 for Exchange 2019](https://support.microsoft.com/KB/5035606) | Environments that are using SSL offloading configuration may face issues with Outlook connectivity issues after upgrading to Exchange 2019 CU14. | As announced in [August 2023](https://techcommunity.microsoft.com/t5/exchange-team-blog/coming-soon-enabling-extended-protection-on-exchange-server-by/ba-p/3911849) , by default, starting with 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](https://learn.microsoft.com/exchange/plan-and-deploy/post-installation-tasks/security-best-practices/exchange-extended-protection?view=exchserver-2019#scenarios-that-could-affect-client-connectivity-when-extended-protection-was-enabled) for more details -2/19/2024 | [CU 14 for Exchange 2019](https://support.microsoft.com/topic/5036404) | 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.
| Please follow the steps from [this KB](https://support.microsoft.com/topic/5036404) to resolve the issue -11/23/2023 | [November 2023 Security Update](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-november-2023-exchange-server-security-updates/ba-p/3980209) for Exchange 2016, Exchange 2019 | 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" | The error can occur if the Exchange server auth certificate has expired. Solution is to renew the [Exchange server auth certificate manually](https://learn.microsoft.com/exchange/troubleshoot/administration/cannot-access-owa-or-ecp-if-oauth-expired) or by using [this script](https://microsoft.github.io/CSS-Exchange/Admin/MonitorExchangeAuthCertificate/) -10/12/2023|[All versions of August 2023 Security Update](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-august-2023-exchange-server-security-updates/ba-p/3892811) for Exchange 2016, Exchange 2019 | 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](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-august-2023-exchange-server-security-updates/ba-p/3892811)

**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.|** Update on 10/12/2023 **

Follow steps on [this article](https://support.microsoft.com/topic/users-in-account-forest-can-t-change-expired-password-in-owa-in-multi-forest-exchange-deployments-after-installing-august-2023-su-b17c3579-0233-4d84-9245-755dd1092edb) -8/15/2023|[Non-English August 2023 Security Update](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-august-2023-exchange-server-security-updates/ba-p/3892811) for Exchange 2016, Exchange 2019 | 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. |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 recommend to uninstall the KB5029388 to avoid issues down the line. For more information please check out [this KB](https://support.microsoft.com/topic/exchange-server-2019-and-2016-august-2023-security-update-installation-fails-on-non-english-operating-systems-ef38d805-f645-4511-8cc5-cf967e5d5c75). -6/15/2023|[January 2023 Security Update](https://www.microsoft.com/en-us/download/details.aspx?id=104914) for Exchange 2016, Exchange 2019 | 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 following error message:

[ERROR] The operation couldn't be performed because object '' couldn't be found on ''. |Install Exchange Security Update June 2023 or higher to resolve the issue. Check [this KB](https://support.microsoft.com/help/5025312) for more details -6/15/2023|Extended protection enabled on Exchange server | 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.`| Install Exchange Security Update June 2023 or higher Security Update and create the setting override mentioned in [this KB](https://support.microsoft.com/topic/extended-protection-doesn-t-support-public-folder-client-permissions-management-through-outlook-bd2037b5-40e0-413a-b368-746b3f5439ee) -|3/16/2023| [Outlook client update for CVE-2023-23397 released](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-23397)| 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](https://msrc.microsoft.com/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](https://msrc.microsoft.com/update-guide/vulnerability/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).** | **Please check [this page](https://aka.ms/OLKCVEFAQ) for FAQs about the [Outlook CVE-2023-23397](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-23397)** -3/14/2023|[February 2023 Security Update](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-february-2023-exchange-server-security-updates/ba-p/3741058) for Exchange 2016, Exchange 2019, Exchange 2013 | After installing February 2023 security update, customers are seeing EWS application pool crash with Event ID 4999 with following error

E12IIS, c-RTL-AMD64, 15.01.2507.021, w3wp#MSExchangeServicesAppPool, M.Exchange.Diagnostics, M.E.D.ChainedSerializationBinder.EnforceBlockReason, M.E.Diagnostics.BlockedDeserializeTypeException, 437c-dumptidset, 15.01.2507.021.

The issue is causing connectivity issues to EWS based clients (Outlook for Mac) | **Update on 3/14/2023**
The issue is fixed in [March 2023 security update for Exchange servers](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-march-2023-exchange-server-security-updates/ba-p/3764224)
Please follow the steps in [this KB](https://support.microsoft.com/help/5024257) -3/14/2023|[February 2023 Security Update](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-february-2023-exchange-server-security-updates/ba-p/3741058) for Exchange 2016, Exchange 2019, Exchange 2013 | Some customers are reporting issues with Outlook/OWA add-ins, like add-in not listing in EAC or with the Get-App command. Additionally, they may notice EWS application pool crash with Event ID 4999 in the application log of the Exchange server. | **Update on 3/14/2023**
The issue is fixed in [March 2023 security update for Exchange servers](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-march-2023-exchange-server-security-updates/ba-p/3764224) -3/14/2023|[January 2023 Security Update](https://www.microsoft.com/en-us/download/details.aspx?id=104914) for Exchange 2016, Exchange 2019 |The Exchange toolbox may start crashing on launch after [certificate Serialization for PowerShell](https://aka.ms/HC-SerializedDataSigning) is enabled. The error noticed is "Deserialization fails: System.Reflection.TargetInvocationException".

The issue happens only on Exchange 2016 and Exchange 2019| **Update on 3/14/2023**
The issue is fixed in [March 2023 security update for Exchange servers](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-march-2023-exchange-server-security-updates/ba-p/3764224) -|-|-|-|- |-|-| -1/24/2023|[January 2023 Security Update](https://www.microsoft.com/en-us/download/details.aspx?id=104914) for Exchange 2016, Exchange 2019 | After installing January 2023 security update and enabling [certificate signing for serialization of PowerShell](https://aka.ms/HC-SerializedDataSigning), you may find various Exchange commands and scripts (example: RedistributeActiveDatabases.ps1) that use deserialization failing with the error similar to :
Error: "Cannot convert the value of type.....to type" | Use [this script](https://aka.ms/MonitorExchangeAuthCertificate) to update the auth certificate -1/24/2023|[January 2023 Security Update](https://www.microsoft.com/en-us/download/details.aspx?id=104914) for Exchange 2016, Exchange 2019 | RecoverServer will fail at pre-requisites check with following error:
"Exchange Server version Version 15.1 (Build 2507.17) or later must be used to perform a recovery of this server." | **Update on 02/23/2023**
The issue has been fixed in [February 2023 Security Update for Exchange servers](https://support.microsoft.com/KB/5023038), however, the following workaround still needs to be used for servers that are on January 2023 Security Update

**Workaround**
Use the steps in [this](https://learn.microsoft.com/exchange/troubleshoot/setup/version-error-in-recover-server-mode-install) article -1/24/2023|[January 2023 Security Update](https://www.microsoft.com/en-us/download/details.aspx?id=104914) for Exchange 2016 installed on Windows 2012 R2, other versions are not affected |The Exchange services in Automatic start-up mode will not start after reboot of the server. The services start successfully if started manually| **Update on 02/23/2023**
The issue has been fixed in [February 2023 Security Update for Exchange servers](https://support.microsoft.com/KB/5023038) -1/24/2023|[January 2023 Security Update](https://www.microsoft.com/en-us/download/details.aspx?id=104914) for Exchange 2016, Exchange 2019 | Transport header shows the older version of server once January 2023 SU is installed (the build shown seems to be the build of the last CU) | The issue will be addressed in upcoming security update | +| 3/14/2024 | [March 2024 Security Update for Exchange 2019,2016](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-march-2024-exchange-server-security-updates/ba-p/4075348) | After installing the [March 2024 Security Update]((https://techcommunity.microsoft.com/t5/exchange-team-blog/released-march-2024-exchange-server-security-updates/ba-p/4075348)), 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. | Use one of the following workarounds:
1) Use OWA or Outlook online mode for search
2) Disable server assisted search by creating following registry key:
**Path:** HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Search
**Value name:** DisableServerAssistedSearch
**Value type:** REG_DWORD
**Value:** 1 | +| 2/20/2024 | [CU 14 for Exchange 2019](https://support.microsoft.com/KB/5035606) | Environments that are using SSL offloading configuration may face issues with Outlook connectivity issues after upgrading to Exchange 2019 CU14. | As announced in [August 2023](https://techcommunity.microsoft.com/t5/exchange-team-blog/coming-soon-enabling-extended-protection-on-exchange-server-by/ba-p/3911849) , by default, starting with 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](https://learn.microsoft.com/exchange/plan-and-deploy/post-installation-tasks/security-best-practices/exchange-extended-protection?view=exchserver-2019#scenarios-that-could-affect-client-connectivity-when-extended-protection-was-enabled) for more details | +| 2/20/2024 | [CU 14 for Exchange 2019](https://support.microsoft.com/KB/5035606)| Environments that are using SSL offloading configuration may face issues with Outlook connectivity issues after upgrading to Exchange 2019 CU14. | As announced in [August 2023](https://techcommunity.microsoft.com/t5/exchange-team-blog/coming-soon-enabling-extended-protection-on-exchange-server-by/ba-p/3911849) , by default, starting with 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](https://learn.microsoft.com/exchange/plan-and-deploy/post-installation-tasks/security-best-practices/exchange-extended-protection?view=exchserver-2019#scenarios-that-could-affect-client-connectivity-when-extended-protection-was-enabled) for more details | +| 2/19/2024 | [CU 14 for Exchange 2019](https://support.microsoft.com/topic/5036404) | 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.
| Please follow the steps from [this KB](https://support.microsoft.com/topic/5036404) to resolve the issue +| 11/23/2023 | [November 2023 Security Update](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-november-2023-exchange-server-security-updates/ba-p/3980209) for Exchange 2016, Exchange 2019 | 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" | The error can occur if the Exchange server auth certificate has expired. Solution is to renew the [Exchange server auth certificate manually](https://learn.microsoft.com/exchange/troubleshoot/administration/cannot-access-owa-or-ecp-if-oauth-expired) or by using [this script](https://microsoft.github.io/CSS-Exchange/Admin/MonitorExchangeAuthCertificate/) | +| 10/12/2023 | [All versions of August 2023 Security Update](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-august-2023-exchange-server-security-updates/ba-p/3892811) for Exchange 2016, Exchange 2019 | 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](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-august-2023-exchange-server-security-updates/ba-p/3892811)

**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.|** Update on 10/12/2023 **

Follow steps on [this article](https://support.microsoft.com/topic/users-in-account-forest-can-t-change-expired-password-in-owa-in-multi-forest-exchange-deployments-after-installing-august-2023-su-b17c3579-0233-4d84-9245-755dd1092edb) | +| 8/15/2023 | [Non-English August 2023 Security Update](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-august-2023-exchange-server-security-updates/ba-p/3892811) for Exchange 2016, Exchange 2019 | 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. |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 recommend to uninstall the KB5029388 to avoid issues down the line. For more information please check out [this KB](https://support.microsoft.com/topic/exchange-server-2019-and-2016-august-2023-security-update-installation-fails-on-non-english-operating-systems-ef38d805-f645-4511-8cc5-cf967e5d5c75). | +| 6/15/2023 | [January 2023 Security Update](https://www.microsoft.com/en-us/download/details.aspx?id=104914) for Exchange 2016, Exchange 2019 | 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 following error message:

[ERROR] The operation couldn't be performed because object '' couldn't be found on ''. |Install Exchange Security Update June 2023 or higher to resolve the issue. Check [this KB](https://support.microsoft.com/help/5025312) for more details | +| 6/15/2023 |Extended protection enabled on Exchange server | 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.`| Install Exchange Security Update June 2023 or higher Security Update and create the setting override mentioned in [this KB](https://support.microsoft.com/topic/extended-protection-doesn-t-support-public-folder-client-permissions-management-through-outlook-bd2037b5-40e0-413a-b368-746b3f5439ee) | +| 3/16/2023 | [Outlook client update for CVE-2023-23397 released](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-23397)| 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](https://msrc.microsoft.com/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](https://msrc.microsoft.com/update-guide/vulnerability/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).** | **Please check [this page](https://aka.ms/OLKCVEFAQ) for FAQs about the [Outlook CVE-2023-23397](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-23397)** | +| 3/14/2023 | [February 2023 Security Update](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-february-2023-exchange-server-security-updates/ba-p/3741058) for Exchange 2016, Exchange 2019, Exchange 2013 | After installing February 2023 security update, customers are seeing EWS application pool crash with Event ID 4999 with following error

E12IIS, c-RTL-AMD64, 15.01.2507.021, w3wp#MSExchangeServicesAppPool, M.Exchange.Diagnostics, M.E.D.ChainedSerializationBinder.EnforceBlockReason, M.E.Diagnostics.BlockedDeserializeTypeException, 437c-dumptidset, 15.01.2507.021.

The issue is causing connectivity issues to EWS based clients (Outlook for Mac) | **Update on 3/14/2023**
The issue is fixed in [March 2023 security update for Exchange servers](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-march-2023-exchange-server-security-updates/ba-p/3764224)
Please follow the steps in [this KB](https://support.microsoft.com/help/5024257) | +| 3/14/2023 | [February 2023 Security Update](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-february-2023-exchange-server-security-updates/ba-p/3741058) for Exchange 2016, Exchange 2019, Exchange 2013 | Some customers are reporting issues with Outlook/OWA add-ins, like add-in not listing in EAC or with the Get-App command. Additionally, they may notice EWS application pool crash with Event ID 4999 in the application log of the Exchange server. | **Update on 3/14/2023**
The issue is fixed in [March 2023 security update for Exchange servers](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-march-2023-exchange-server-security-updates/ba-p/3764224) | +| 3/14/2023 | [January 2023 Security Update](https://www.microsoft.com/en-us/download/details.aspx?id=104914) for Exchange 2016, Exchange 2019 |The Exchange toolbox may start crashing on launch after [certificate Serialization for PowerShell](https://aka.ms/HC-SerializedDataSigning) is enabled. The error noticed is "Deserialization fails: System.Reflection.TargetInvocationException".

The issue happens only on Exchange 2016 and Exchange 2019| **Update on 3/14/2023**
The issue is fixed in [March 2023 security update for Exchange servers](https://techcommunity.microsoft.com/t5/exchange-team-blog/released-march-2023-exchange-server-security-updates/ba-p/3764224) | +|-|-|-|-|-|-| +| 1/24/2023 | [January 2023 Security Update](https://www.microsoft.com/en-us/download/details.aspx?id=104914) for Exchange 2016, Exchange 2019 | After installing January 2023 security update and enabling [certificate signing for serialization of PowerShell](https://aka.ms/HC-SerializedDataSigning), you may find various Exchange commands and scripts (example: RedistributeActiveDatabases.ps1) that use deserialization failing with the error similar to :
Error: "Cannot convert the value of type.....to type" | Use [this script](https://aka.ms/MonitorExchangeAuthCertificate) to update the auth certificate | +| 1/24/2023 | [January 2023 Security Update](https://www.microsoft.com/en-us/download/details.aspx?id=104914) for Exchange 2016, Exchange 2019 | RecoverServer will fail at pre-requisites check with following error:
"Exchange Server version Version 15.1 (Build 2507.17) or later must be used to perform a recovery of this server." | **Update on 02/23/2023**
The issue has been fixed in [February 2023 Security Update for Exchange servers](https://support.microsoft.com/KB/5023038), however, the following workaround still needs to be used for servers that are on January 2023 Security Update

**Workaround**
Use the steps in [this](https://learn.microsoft.com/exchange/troubleshoot/setup/version-error-in-recover-server-mode-install) article | +| 1/24/2023 | [January 2023 Security Update](https://www.microsoft.com/en-us/download/details.aspx?id=104914) for Exchange 2016 installed on Windows 2012 R2, other versions are not affected |The Exchange services in Automatic start-up mode will not start after reboot of the server. The services start successfully if started manually| **Update on 02/23/2023**
The issue has been fixed in [February 2023 Security Update for Exchange servers](https://support.microsoft.com/KB/5023038) | +| 1/24/2023 | [January 2023 Security Update](https://www.microsoft.com/en-us/download/details.aspx?id=104914) for Exchange 2016, Exchange 2019 | Transport header shows the older version of server once January 2023 SU is installed (the build shown seems to be the build of the last CU) | The issue will be addressed in upcoming security update |