autounattend.xml contains invalid <Extensions> element causing Windows Setup to ignore file

[Sam22453]

Hi, I used the provided autounattend.xml on a Windows 11 installation USB, but Windows Setup ran as if no answer file was present.

When validating the autounattend.xml file using Windows System Image Manager , I received the following error pop-up:

Validation error on D:\autounattend.xml, line 1031, column 4.

Details: The element 'unattend' in namespace 'urn:schemas-microsoft-com:unattend' has invalid child element 'Extensions' in namespace 'urn:schemas-microsoft-com:unattend'. List of possible elements expected: 'settings' in namespace 'urn:schemas-microsoft-com:unattend' as well as any element in namespace '##other'.

[ClaudiusCluever]

I seem to have the same issue as the install progressed as without unattended winstall. I didn't verify by validating the autounattend.xml file using Windows System Image Manager, though.

[memstechtips]

Hey there and thanks for reporting this.

@Sam22453

Details: The element 'unattend' in namespace 'urn:schemas-microsoft-com:unattend' has invalid child element 'Extensions' in namespace 'urn:schemas-microsoft-com:unattend'. List of possible elements expected: 'settings' in namespace 'urn:schemas-microsoft-com:unattend' as well as any element in namespace '##other'.

This was due to a missing xml namespace, I have added one now and the Windows System Image Manager does not error out anymore.

Please note that this did not affect the functionality of the answer file, only the ability for SIM to recognize and read it.

@ClaudiusCluever

I seem to have the same issue as the install progressed as without unattended winstall. I didn't verify by validating the autounattend.xml file using Windows System Image Manager, though.

I have just updated v3.0.0 of the answer file and did a clean install with the file on Windows 11 25H2 and it worked without any issues, see the screenshot below.

Which installation method are you using? How did you create the installation media? Can you look at C:\ProgramData\Winhance\Unattend and see if there is anything inside that folder or not?

[ClaudiusCluever]

Thank you for your answer!

I used the instructions on the project page, so I used WIMUtil and Ventoy.

Which installation method are you using? How did you create the installation media? Can you look at C:\ProgramData\Winhance\Unattend and see if there is anything inside that folder or not?

You mean in the finished install?