Microsoft has released the following Windows 10 updates: KB4534321 for Windows 10, version 1809, Windows Server version 1809, Windows Server 2019, all versions, KB4534318 for Windows 10, version 1709, KB4534308 for Windows 10, version 1803, and KB4534307 for Windows 10, version 1607 and Windows Server 2016.

January 23, 2020—KB4534321 (OS Build 17763.1012)

Highlights

• Updates an issue with Windows Mixed Reality that occurs after upgrading to a new version of Microsoft Edge. 
• Updates an issue that causes a device to repeatedly go into the Windows Out Of Box Experience (OOBE) restart loop in certain situations. 
• Updates an issue that causes the touch keyboard to close when you select any key. 
• Updates an issue that prevents users from reducing the size of a window in some cases. 
• Updates an issue that changes the user-customized order of tiles in the Start menu even though the layout is locked or partially locked. 
• Updates an issue that causes the Settings page to close unexpectedly.
• Updates an issue that might prevent a user’s settings from syncing across devices. 

Improvements and fixes

This non-security update includes quality improvements. Key changes include:

• Addresses an issue with Windows Mixed Reality that occurs after upgrading to a new version of Microsoft Edge. 
• Addresses an issue with download notifications that have multiple short-duration tabs and redirects. 
• Addresses an issue that causes the Microsoft Windows Search Indexer (searchindexer.exe) to add or repair required access control lists (ACLs) without checking if ACLs exist. 
• Addresses an issue that causes a device to repeatedly go into the Windows Out Of Box Experience (OOBE) restart loop in certain situations. 
• Addresses an issue with syncing settings from the Accounts page when the "Continue experiences on this device" Group Policy is disabled. 
• Addresses an issue that prevents software Indirect Display drivers from being signed with more than one certificate. 
• Addresses an issue with a memory leak in ctfmon.exe that occurs when you refresh an application that has an editable box. 
• Addresses an issue that, in some instances, prevents the Language Bar from appearing when the user signs in to a new session. This occurs even though the Language Bar is configured properly. 
• Addresses an issue that causes the touch keyboard to close when you select any key. 
• Addresses an issue that prevents users from reducing the size of a window in some cases. 
• Addresses an issue that changes the user-customized order of tiles in the Start menu even though the layout is locked or partially locked. 
• Addresses an issue with incorrect permissions on a user’s class registry keys that might prevent users that have local or roaming user profiles from opening files, links, and applications. 
• Addresses an issue that causes the Settings page to close unexpectedly, which prevents default applications from being set properly. 
• Addresses an issue that causes Windows Search to close unexpectedly when a Group Policy applies sub-groups to the Start menu layout. 
• Addresses an issue with the multifactor unlock policy of Windows Hello for Business that fails to show the default option to sign in on Windows 10 devices. 
• Addresses an issue that prevents a remote PowerShell session job from reporting that the session on the target machine has ended. 
• Addresses an issue with a handle leak in the EnableTraceEx2() function. 
• Addresses an issue that prevents Internet Explorer from opening when Microsoft User Experience Virtualization (UE-V) is being used to roam many favorites. 
• Improves the reliability of the UE-V AppMonitor. 
• Addresses an issue that might prevent a user’s settings from syncing across devices. 
• Addresses an issue that causes the Local Security Authority Subsystem Service (LSASS) process to stop working when you sign in using an updated user principal name (UPN) (for example, changing UserN@contoso.com to User.Name@contoso.com). The error code is, “0xc0000005 (STATUS_ACCESS_VIOLATION).”  
• Addresses an issue with unsigned program files that will not run when Windows Defender Application Control is in Audit Mode, but will allow unsigned images to run. 
• Addresses an issue that might cause the Print Management console to display script errors when you enable the Extended View option.
• Addresses an issue with the Always On Virtual Private Network (VPN) that fails to remove the Name Resolution Policy Table (NRPT) rules after you disconnect. 
• Addresses an issue with AppContainer firewall rules that leak when guest users or mandatory user profile users sign in and sign out from Windows Server. 
• Addresses an issue that causes some systems to stop responding when operating embedded MultiMediaCard (eMMC) storage devices. 
• Addresses an issue with ntdsutil.exe that prevents you from moving Active Directory database files. The error is, “Move file failed with source and Destination with error 5 (Access is denied.)” 
• Addresses an issue in which netdom.exe fails to correctly identify trust relationships when an unconstrained delegation is explicitly enabled by adding bitmask 0x800 to the trust object. The bitmask setting is required because of security changes to the default behavior of unconstrained delegations in Windows updates released on or after July 8, 2019. For more information, see KB4490425 and 6.1.6.7.9 trustAttributes. 
• Addresses an issue that uses an incorrect number of bytes to perform backups across partitions; this causes backups to fail even when there is adequate space. 
• Addresses an issue with evaluating the compatibility status of the Windows ecosystem to help ensure application and device compatibility for all updates to Windows. 
• Addresses an issue with the Windows Out of Box Experience (OOBE) phase of setup for a new device. When you use the Input Method Editor (IME) for Chinese, Japanese, or Korean languages, you might not be able to create a local user account.
• Addresses an issue that corrupts a log file when a storage volume is full and data is still being written to the Extensible Storage Engine Technology (ESENT) database.
• Addresses an issue that might cause the Application Virtualization (App-V) Streaming Driver (appvstr.sys) to leak memory when you enable Shared Content Store (SCS) mode.
• Improves the performance of block cloning for the Resilient File System (ReFS) in scenarios that involve a large number of operations on ReFS-cloned files.

If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.

January 23, 2020—KB4534321 (OS Build 17763.1012)

January 23, 2020—KB4534318 (OS Build 16299.1654)

Highlights

• Updates an issue that might prevent a user’s settings from syncing across devices. 

Improvements and fixes

This non-security update includes quality improvements. Key changes include:

• Addresses an issue that prevents computer objects from being added to local groups using the Group Policy Preference “Local Users and Groups”. The Group Policy Editor returns the error message, “The object selected does not match the type of destination source. Select again.” 
• Addresses an issue that prevents Internet Explorer from opening when Microsoft User Experience Virtualization (UE-V) is being used to roam many favorites. 
• Improves the reliability of the UE-V AppMonitor. 
• Addresses an issue that might prevent a user’s settings from syncing across devices. 
• Addresses an issue with evaluating the compatibility status of the Windows ecosystem to help ensure application and device compatibility for all updates to Windows. 
• Addresses an issue with the Windows Out of Box Experience (OOBE) phase of setup for a new device. When you use the Input Method Editor (IME) for Chinese, Japanese, or Korean languages, you might not be able to create a local user account.

• Addresses an issue that might cause the Application Virtualization (App-V) Streaming Driver (appvstr.sys) to leak memory when you enable Shared Content Store (SCS) mode.

If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.

January 23, 2020—KB4534318 (OS Build 16299.1654)

January 23, 2020—KB4534308 (OS Build 17134.1276)

Highlights

• Updates an issue that might prevent a user’s settings from syncing across devices. 

Improvements and fixes

This non-security update includes quality improvements. Key changes include:

• Addresses an issue with using Web Account Manager to sign in to Office Apps. 
• Addresses an issue with download notifications that have multiple short-duration tabs and redirects. 
• Addresses an issue with a memory leak in ctfmon.exe that occurs when you refresh an application that has an editable box. 
• Addresses an issue with the Windows Out of Box Experience (OOBE) phase of setup for a new device. When you use the Input Method Editor (IME) for Chinese, Japanese, or Korean languages, you might not be able to create a local user account. 
• Addresses an issue with the multifactor unlock policy of Windows Hello for Business, which fails to show the default option to sign in on Windows 10 devices. 
• Addresses an issue that prevents computer objects from being added to local groups using the Group Policy Preference “Local Users and Groups”. The Group Policy Editor returns the error message, “The object selected does not match the type of destination source. Select again.” 
• Addresses an issue that prevents Internet Explorer from opening when Microsoft User Experience Virtualization (UE-V) is being used to roam many favorites. 
• Improves the reliability of the UE-V AppMonitor. 
• Addresses an issue that might prevent a user’s settings from syncing across devices. 
• Addresses an issue that might cause high CPU consumption in Microsoft Defender Advanced Threat Protection when using Microsoft Teams. 
• Addresses an issue that causes the Local Security Authority Subsystem Service (LSASS) process to stop working when you sign in using an updated user principal name (UPN) (for example, changing UserN@contoso.com to User.Name@contoso.com). The error code is, “0xc0000005 (STATUS_ACCESS_VIOLATION).” 
• Addresses an issue that causes a connection secured by IP security (IPSec) Internet Key Exchange Version 1 (IKEv1) to consume multiple, short-lived security associations (SA) instead of utilizing one until it expires. 
• Addresses an issue with AppContainer firewall rules that leak when guest users or mandatory user profile users sign in and sign out from Windows Server. 
• Addresses an issue that uses an incorrect number of bytes to perform backups across partitions; this causes backups to fail even when there is adequate space. 
• Addresses an issue with evaluating the compatibility status of the Windows ecosystem to help ensure application and device compatibility for all updates to Windows.
• Addresses an issue in which netdom.exe fails to correctly identify trust relationships when an unconstrained delegation is explicitly enabled by adding bitmask 0x800 to the trust object. The bitmask setting is required because of security changes to the default behavior of unconstrained delegations in Windows updates released on or after July 8, 2019. For more information, see KB4490425 and 6.1.6.7.9 trustAttributes. 
• Addresses an issue that might cause the Application Virtualization (App-V) Streaming Driver (appvstr.sys) to leak memory when you enable Shared Content Store (SCS) mode.
• Addresses an issue that corrupts a log file when a storage volume is full and data is still being written to the Extensible Storage Engine Technology (ESENT) database.

If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.

January 23, 2020—KB4534308 (OS Build 17134.1276)

January 23, 2020—KB4534307 (OS Build 14393.3474)

Highlights

• Updates an issue that might sometimes occur in Microsoft Word when you change to Focus mode using the Korean Windows Input Method Editor (IME). 

Improvements and fixes

This non-security update includes quality improvements. Key changes include:

• Addresses an issue that might sometimes occur in Microsoft Word when you change to Focus mode using the Korean Windows Input Method Editor (IME). 
• Addresses an issue that occurs after you sign in, which causes an application to stop responding when you use the IME with the touch keyboard. 
• Addresses an issue that might prevent you from signing in to a new Remote Desktop console session or reconnecting to an existing session on a device that has reached its active session limit. If attempts to sign in do not fail immediately, you might also experience a long wait at the Welcome screen. The error message is, “The task you are trying to do can't be completed because Remote Desktop Services is currently busy. Please try again in a few minutes. Other users should still be able to log on.” 
• Addresses a race condition that occurs when you run multiple PowerShell scripts simultaneously. 
• Improves the reliability of the Microsoft User Experience Virtualization (UE-V) AppMonitor. 
• Addresses an issue that might cause Direct Access servers to use a large amount of non-paged pool memory (pooltag: NDnd). 
• Addresses an issue with AppContainer firewall rules that leak when guest users or mandatory user profile users sign in and sign out from Windows Server. 
• Addresses an issue that causes queries against large keys on Ntds.dit to fail with the error, “MAPI_E_NOT_ENOUGH_RESOURCES.” 
• Addresses an Open Database Connectivity (ODBC) issue that causes an infinite loop in the retry logic when there are several lost connections in the connection pool. 
• Addresses an issue that fails to apply the defined connection values for Remote Desktop Services (RDS).
• Addresses an issue that uses an incorrect number of bytes to perform backups across partitions; this causes backups to fail even when there is adequate space. 
• Addresses an issue in which netdom.exe fails to correctly identify trust relationships when an unconstrained delegation is explicitly enabled by adding bitmask 0x800 to the trust object. The bitmask setting is required because of security changes to the default behavior of unconstrained delegations in Windows updates released on or after July 8, 2019. For more information, see KB4490425 and 6.1.6.7.9 trustAttributes. 
• Addresses an issue with evaluating the compatibility status of the Windows ecosystem to help ensure application and device compatibility for all updates to Windows. 
• Addresses an issue that might cause the Application Virtualization (App-V) Streaming Driver (appvstr.sys) to leak memory when you enable Shared Content Store (SCS) mode.

If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.

January 23, 2020—KB4534307 (OS Build 14393.3474)