Download update KB4493509 for Windows 10 Version 1809 Build 17763.437

With the update KB4493509 for Windows 10 version 1809 , Microsoft released another cumulative update on Patchday in Apil 2019.

The update  KB4493509 is now available via the Windows Update Catalog and the Windows Update function of Windows 10. In addition to improvements, the update also includes numerous bug fixes.

After installing the update KB4493509 , your Windows 10 build number shows 17763.437 .

The following information has so far become known about the update  KB4493509 .

  • The KB4493509 update resolves an issue that occurs when you enable custom end-user characters (EUDC). The system no longer works and a blue screen appears at startup . This is not common in non-Asian regions.
  • It also fixes an issue where applications using MSXML6 would stop responding if an exception was raised during node operations.
  • Addresses an issue that causes Group Policy Editor to stop responding when editing a Group Policy Object (GPO) with Group Policy Settings (GPP) for Internet Explorer 10 Internet Settings.
  • Addresses an issue that could cause authentication problems for Internet Explorer 11 and other applications that use WININET.DLL. This occurs when two or more people use the same user account for multiple concurrent logon sessions on the same Windows Server computer, including Remote Desktop Protocol (RDP) and Terminal Server logons.
  • Furthermore, the update KB4493509 includes numerous security updates for Windows Datacenter Networking, Windows Server, Microsoft JET Database Engine, Windows Kernel, Windows input and composition, Microsoft Scripting Engine, Windows App Platform and Frameworks, Windows memory and file systems, Microsoft graphics component, Windows Virtualization, Windows MSXML, Windows SQL components and Microsoft Edge.


The following problems are already known with this update KB4493509 .

Error 1:

After installing this update, custom application protocol handler URI schemes cannot start the appropriate intranet and trusted sites application in Internet Explorer.

Microsoft offers the following workaround:
Activate the protected mode in Internet Explorer for local intranet and trusted sites.
Go to Tools> Internet Options> Security.
Under Select a zone to view or change security settings, select Local intranet and then Enable protected mode.
Select Trusted Sites and then turn on Protected Mode.
Choose OK.
You will need to restart the browser after making these changes.

Mistake 2:

After installing this update, you may experience problems with the Preboot Execution Environment (PXE) to start a device from a Windows Deployment Services (WDS) server that is configured to use the variable window extension. This may result in the connection to the WDS server being terminated prematurely while the image is being downloaded. This problem does not affect clients or devices that do not use the Window Extension variable.

Microsoft offers the following workaround:
Deactivate the variable window extension on the WDS server with one of the following options to correct the problem:

Option 1:
Open an administrator command prompt and type the following:
Wdsutil / Set-TransportServer / EnableTftpVariableWindowExtension: No.

Option 2:
Use the Windows Deployment Services user interface.
Open Windows Deployment Services from Windows Management.
Expand Server and right click on a WDS server.
Open the properties and clear the Extend Variable Window check box on the TFTP tab.

Option 3:
Set the following registry
value to 0: “HKLM System CurrentControlSet Services WDSServer Providers WDSTFTP EnableVariableWindowExtension”.
Restart the WDSServer service after deactivating the variable window extension.
Microsoft is working on a solution and will provide an update in an upcoming version.

If you are aware of further errors or problems or if you have problems installing the update KB4493509 , please leave a comment with a detailed description of the problem.

Here you can download the update KB4493509 :

– 2019-04 Cumulative update for Windows 10 version 1809 for x64-based systems (KB4493509)
– 2019-04 Cumulative update for Windows 10 version 1809 for x86-based systems (KB4493509)
– 2019-04 Cumulative update for Windows Server 2019 version 1809 for x64-based systems (KB4493509)