Import-WdsInstallImage : An install image could not be found in the image file.

Hello,

The WDS server is a freshly installed Win 2019 server.

I am trying to import install images with PowerShell.

$ImagePath = 'D:\Sources\2019\install.wim'
$ImageName = (Get-WindowsImage -ImagePath $ImagePath -Index 4).ImageName
Import-WdsInstallImage -ImageGroup 'Win2019' -ImageName $ImageName -Path $ImagePath -Multicast

However I get the following error:

Import-WdsInstallImage : An install image could not be found in the image file.
At line:3 char:1+ Import-WdsInstallImage -ImageGroup 'Win2019' -ImageName $ImageName -P ...+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+ CategoryInfo          : NotSpecified: (MSFT_WdsInstallImage:root/cimv2/MSFT_WdsInstallImage) [Import-WdsInstallImage], CimException+ FullyQualifiedErrorId : 0xC111010E,Import-WdsInstallImage

The image file is NOT read-only.

And with the console it works fine.

I also installed the latest system rollup, but the behavior is the same.

Does anybody see what's wrong with my code?