Blank Screen during OOBE (Windows 11 IoT Enterprise LTSC 2024) when Custom Shell is enabled using Shell Launcher V2

Mark Bewley 31

I am getting a blank screen during OOBE if a custom shell is enabled, using the Shell Launcher V2 capability (CustomShellHost.exe).

Evaluating the latest Win11 IoT Enterprise LTSC 2024 release we boot to Audit mode. A simple unattend.xml is specified to sysprep to OOBE.

After the "Just a moment..." screen disappears it just displays a blank screen (mouse cursor shows and there is regular drive light activity). If power cycled, it shows the "Just a moment..." screen again, but after a few seconds of blank scree, the OOBE screens are displayed.

I have seen the OOBE screens correctly display if a network cable is attached - but not been able to replicate this in more recent testing.

Sean Liming 4,601 Reputation points

2024-09-27T16:23:20.8433333+00:00

If you do a plain clean install of Win11 IoT Enterprise LTSC 2024 without using an answer file does the system boot up properly? If sysprep without using an answer file, does the system boot up correctly?

Mark Bewley 31

A plain image booted up properly, so I started again adding features back in.

I have tracked down a possible cause, to enabling of a custom shell (during Audit mode).

<?xml version="1.0" encoding="utf-8"?>
<ShellLauncherConfiguration xmlns="http://schemas.microsoft.com/ShellLauncher/2018/Configuration"
xmlns:v2="http://schemas.microsoft.com/ShellLauncher/2019/Configuration">
    <Profiles>
        <DefaultProfile>
            <Shell Shell="%systemroot%\explorer.exe">
                <DefaultAction Action="RestartShell"/>
            </Shell>
        </DefaultProfile>
        <Profile Id="{4B5F92B0-C10E-40AD-A25D-0F9C0224BAB1}">
            <Shell Shell="%systemroot%\explorer.exe">
                <DefaultAction Action="RestartShell"/>
            </Shell>
        </Profile>
        <Profile Id="{4B5F92B0-C10E-40AD-A25D-0F9C0224BAB2}">
            <Shell Shell="%windir%\OEM\CustomShell.exe">
                <ReturnCodeActions>
                    <ReturnCodeAction ReturnCode="0" Action="RestartShell"/>
                    <ReturnCodeAction ReturnCode="-1" Action="RestartDevice"/>
                    <ReturnCodeAction ReturnCode="255" Action="ShutdownDevice"/>
                    <ReturnCodeAction ReturnCode="1" Action="DoNothing"/>
                </ReturnCodeActions>
                <DefaultAction Action="RestartShell"/>
            </Shell>
        </Profile>
    </Profiles>
    <Configs>
        <Config>
            <!-- Sid can be user sid, local group sid, and AD group sid -->
            <Account Sid="S-1-5-32-544"/>
            <Profile Id="{4B5F92B0-C10E-40AD-A25D-0F9C0224BAB1}"/>
        </Config>
        <Config>
            <!-- Sid can be user sid, local group sid, and AD group sid -->
            <Account Sid="S-1-5-32-545"/>
            <Profile Id="{4B5F92B0-C10E-40AD-A25D-0F9C0224BAB2}"/>
        </Config>
    </Configs>
</ShellLauncherConfiguration>

This worked well with our Windows 10 IoT Enterprise LTSC 2021 image.

We preferred the custom shell to launch after OOBE, as we could then run our custom OOBE experience - if the desktop is shown, some end-users failed to complete setup tasks (as we have to trigger elevation to perform tasks).

NOTE: In this round of VM testing network connectivity made no difference.

Mark Bewley 31 Reputation points

2024-10-04T11:33:37.14+00:00

I was aware of the comment in https://learn.microsoft.com/en-us/windows/configuration/assigned-access/shell-launcher

Windows doesn't support setting a custom shell before the out-of-box experience (OOBE). If you do, you can't deploy the resulting image

Although it worked fine under Windows 10 IoT Enterprise LTSC 2021; it may be it is an unsupported usage and we cannot deploy with custom shell enabled.
Mark Bewley 31 Reputation points

2024-10-09T10:31:53.8566667+00:00

Whether this comment is related to the issue I am seeing - or something new.

During testing OOBE options and the unattend.xml I can get into a state where, for each new user login, the standard explorer desktop displays the OOBE-style screens to ask the user to select the location, find my device, diagnostic data, inking & typing, tailored experiences and advertising ID options.

Now if I login with a user that has the custom desktop specified I am just presented with the blank screen.

2 answers

Wesley Li 10,240 Reputation points

2024-09-20T15:49:50.2533333+00:00

Hello

From the information I found, there doesn't seem to be a direct solution to this specific issue. However, here are a few steps you might consider to troubleshoot and potentially resolve the problem:

Check Unattend.xml Configuration: Ensure that your unattend.xml file is correctly configured and does not have any settings that might be causing the issue when there is no network connection.

Review Logs: Check the setup logs located in C:\Windows\Panther and C:\Windows\Panther\UnattendGC for any errors or warnings that might give you more insight into what is causing the blank screen.

Network Dependencies: Verify if there are any network dependencies in your OOBE setup that might be causing the issue. Sometimes, certain configurations or scripts might require a network connection to proceed.

Update Drivers: Ensure that all drivers, especially network drivers, are up to date. Sometimes, outdated drivers can cause unexpected behavior during the OOBE process.
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Mark Bewley 31 Reputation points

2024-09-20T16:30:05.91+00:00

So far, I have reviewed the setup logs in C:\Windows\Panther - nothing obvious.

There was no C:\Windows\Panther\UnattendGC folder (when powered off a blank screen and inspected logs via a WinPE boot stick)

Mark Bewley 31 Reputation points

2024-09-23T13:28:02.9266667+00:00

I have tested without the unattend.xml file, using the Sysprep dialog options (with and without Generalize ticked) and this made no difference.

Mark Bewley 31 Reputation points

2024-09-23T13:28:29+00:00

Is this a known issue?

Mark Bewley 31 Reputation points

2024-09-23T15:05:22.9066667+00:00

I get the same result when installing in a VM (Gen 1) with no network.
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Sean Liming 4,601 Reputation points

2024-10-07T00:20:49.4233333+00:00

@Mark Bewley Per the comments-

If your application is not a UWP application, I recommend using Shell Launcher V1 rather than V2. The Shell Launcher APIs can be used to configure Shell Launcher. My Shell Launcher command line utility can help with the setup: https://annabooks.com/SW_SLUtility.html
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Mark Bewley 31 Reputation points

2024-10-08T17:45:22.33+00:00

Thanks for you feedback. No, our custom shell is not a UWP application. During Windows 10 testing V2 was selected as CustomShellHost.exe seemed to work best with "legacy" system tray apps.

I did try setting V1 from audit mode and sysprep to OOBE - but it bricked, loading to a recovery blue screen. Which is probably inline with the statement:

Windows doesn't support setting a custom shell before the out-of-box experience (OOBE). If you do, you can't deploy the resulting image

But V2 seems to have a different behaviour. Which worked fine on Win 10 but seems have issues interacting with the newer Win 11 OOBE.

Mark Bewley 31 Reputation points

2024-10-08T17:54:00.1766667+00:00

Forgot to mention, I removed the script during Audit mode that enabled the custom shell.

It happily completes the OOBE.

Not my ideal solution; as I would prefer to prevent access to the standard desktop until post-OOBE tasks have been completed. Win 11 is a bit more annoying as it has added the quiet time on first boot\login and displays the start menu.
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Blank Screen during OOBE (Windows 11 IoT Enterprise LTSC 2024) when Custom Shell is enabled using Shell Launcher V2

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