Windows 11 24H2 KB5068221 fixes problems with Office apps

Windows 11 version 24H2 has received an unscheduled update aimed at fixing issues with Office applications.

Windows 11 24h2 image

Microsoft has released an out-of-band update for Windows 11 version 24H2 to address problems with Microsoft Office applications in certain environments. KB5068221 is now available for download with build number 26100.6588. Its changelog contains only one fix, which is typical for unscheduled updates:

[Virtualization and platform compatibility] Fixed: This update addresses an issue that affects Microsoft Office applications running in Microsoft Application Virtualization (App-V) environments. The failure occurred due to a double handle closure in the AppVEntSubsystems32 or AppVEntSubsystems64 system component.

The update includes a single known issue that originates from previous updates, particularly this month's security update under KB5065426 (it also has issues with DRM/HDCP playback). Affected systems have problems connecting to shared files and folders using SMB v1:

Symptoms	Workaround
After installing this Windows update released on or after September 9, 2025, you might fail to connect to shared files and folders using the Server Message Block (SMB) v1 protocol on NetBIOS over TCP/IP (NetBT). This issue can occur if either the SMB client or the SMB server has the September 2025 security update installed. Note: The SMBv1 protocol is deprecated and no longer installed by default in modern versions of Windows and Windows Server. Deployments that use newer versions of the protocol, SMBv2 or SMBv3, are not affected by this problem.	You can work around this issue by allowing network traffic on TCP port 445. By doing so, the Windows SMB connection will automatically switch to using TCP instead of NetBT, allowing the connection to resume successfully. We are working on a resolution in a future Windows update and will provide more information when it is available.

Symptoms

Workaround

After installing this Windows update released on or after September 9, 2025, you might fail to connect to shared files and folders using the Server Message Block (SMB) v1 protocol on NetBIOS over TCP/IP (NetBT). This issue can occur if either the SMB client or the SMB server has the September 2025 security update installed.

Note: The SMBv1 protocol is deprecated and no longer installed by default in modern versions of Windows and Windows Server. Deployments that use newer versions of the protocol, SMBv2 or SMBv3, are not affected by this problem.

You can work around this issue by allowing network traffic on TCP port 445. By doing so, the Windows SMB connection will automatically switch to using TCP instead of NetBT, allowing the connection to resume successfully.

We are working on a resolution in a future Windows update and will provide more information when it is available.

You can download KB5068221 by heading to Settings > Windows Update. It is also available in the Microsoft Update Catalog via this link. Alongside the release, Microsoft reminded users that the original Secure Boot certificates are expiring, and customers should prepare for an upgrade. If you want to know more about this, check out this article.