KB4534307

• Updates 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 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. To enable the changes, add a new registry key, “DeleteUserAppContainersOnLogoff” (DWORD) on “HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy” using Regedit, and set it to 1.

• Addresses an issue that causes queries against large keys on Ntds.dit to fail with the error, “MAPI_E_NOT_ENOUGH_RESOURCES.” This issue might cause users to see limited meeting room availability because the Exchange Messaging Application Programming Interface (MAPI) cannot allocate additional memory for the meeting requests.

• 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.

• Addresses an issue in which code refactoring breaks optimization for writing metadata, which increases Logical Volume Integrity Descriptors (LVID).

• Addresses an issue that causes CPU utilization to increase even when running idle.

• Adds support for modern credentials that don’t require passwords (Fast Identity Online 2 (FIDO2) security keys) in hybrid Azure Active Directory-joined environments.