Das Kumulative Update KB4489889 (OS Build 14393.2879) für Windows Server 2016 und Windows 10 1607 (LTSB) kann unter bestimmten Umständen dazu führen, dass das Laden von Abbildern über WDS nicht mehr funktioniert.

Im Changelog zu diesem Update heißt es:

After installing this update, there may be issues using the Preboot Execution Environment (PXE) to start a device from a Windows Deployment Services (WDS) server configured to use Variable Window Extension. This may cause the connection to the WDS server to terminate prematurely while downloading the image. This issue does not affect clients or devices that are not using Variable Window Extension.

Vorübergehender Workaround:

Option 1:
Open an Administrator Command prompt and type the following:

Wdsutil /Set-TransportServer /EnableTftpVariableWindowExtension:No

Option 2:
Use the Windows Deployment Services UI.

1. Open Windows Deployment Services from Windows Administrative Tools.
2. Expand Servers and right-click a WDS server.
3. Open its properties and clear the Enable Variable Window Extension 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 disabling the Variable Window Extension.