[Bug] Issue with WebView2 version in .NET9 MAUI for Windows platform

[unrateddi]

Library version used

4.66.2

.NET version

.NET 9

Scenario

PublicClient - desktop app, PublicClient - mobile app

Is this a new or an existing app?

This is a new app or experiment

Issue description and reproduction steps

When building our .NET 9 MAUI application in Windows platform, we face issues with WebView2.
Specifically it seems that Microsoft.Client.Identity uses an older version of it than the one .NET 9 MAUI uses.
We thought we could work around it by referencing directly the older version and log-in flow works fine, but then we are unable to use a WebView control in the app since MAUI looks explicitly for the newer version. Maybe the library should reference the newer WebView2 at least for .NET 9 MAUI?

This can be reproduced easily in the samples of this repo by upgrading to .NET 9 and upgrading nuget packages.
Unfortunately, this is not the only issue we faced in .NET 9 MAUI, as there is another issue here that when referencing Microsoft.Identity.Client.Desktop the app won't compile. So in order to reproduce our issue you need to do the workaround mentioned here.

Repro steps:

1. Upgrade to .NET 9
2. Use workaround from here to be able to compile the app
3. Disable Warnings as Errors (NU1605)
4. Directly reference (downgrade) Microsoft.Web.WebView2 version 1.0.864.35
5. Add a WebView control in the MainView.xaml

Relevant code snippets

<NoWarn>NU1605</NoWarn>

<PackageReference Include="Microsoft.Web.WebView2" Version="1.0.864.35" />


<ItemGroup>
    <DefaultReferenceExclusion Include="WindowsFormsIntegration" />
</ItemGroup>

<Target Name="RemoveWindowsFormsIntegration" BeforeTargets="MarkupCompilePass1" AfterTargets="ResolveAssemblyReferences">
    <ItemGroup>
	    <_referenceExclusion Include="@(DefaultReferenceExclusion)">
		    <AssemblyName>%(DefaultReferenceExclusion.Identity)</AssemblyName>
	    </_referenceExclusion>
	    <ReferencePath Remove="@(_referenceExclusion)" MatchOnMetadata="AssemblyName" />
    </ItemGroup>
</Target>

Expected behavior

The library and SignIn flow in .NET 9 MAUI for Windows platform should work without having to directly reference some older WebView2 version in the project.

Identity provider

Azure B2C Basic Policy

Regression

No response

Solution and workarounds

No response

[MarcelWolterbeek]

We run into the same issue on .NET 9. We need the WebView in our Windows Maui app and Microsoft.Client.IdentityDesktop for logging on. WebView does not work when we downgrade Microsoft.Web.WebView2 to version 1.0.864.35

If we do not downgrade, we get this exception message when logging on:
Could not load file or assembly 'Microsoft.Web.WebView2.Core, Version=1.0.864.35, Culture=neutral, PublicKeyToken=2a8ab48044d2601e'. The system cannot find the file specified.

This is interestingly, because the Microsoft.Client.IdentityDesktop package states it needs Microsoft.Web.WebView2 >= 1.0.864.35, so it should work with Microsoft.Web.WebView2 version 1.0.2792.45

The problem in both situations is the DLL reference:
1.0.864.35 is using Microsoft.Web.WebView2.Core
1.0.2792.45 is using Microsoft.Web.WebView2.Core.Projection

So please fix the direct reference to the dll!

This is an urgent issue for us, because we need nuget packages with fixes only available in the .NET9 version in our app.

[panta2705]

I reported basically same issue here as well, #4933, hopefully some fix will be around soon, it's a blocking issue

[espenrl]

Microsoft.Identity.Client.Desktop uses an older version of Microsoft.Web.WebView2. 1.0.864.35 was released June 1st 2021.

microsoft-authentication-library-for-dotnet/Directory.Packages.props

Line 16 in 90e8fc9

<PackageVersion Include="Microsoft.Web.WebView2" Version="1.0.864.35" />

The DLL structure has changed (though Microsoft.Web.WebView2.Core.dll is present in both.) Please see internals of packages

• https://www.nuget.org/packages/Microsoft.Web.WebView2/1.0.864.35#versions-body-tab
• https://nuget.info/packages/Microsoft.Web.WebView2/1.0.864.35
• https://nuget.info/packages/Microsoft.Web.WebView2/1.0.2903.40 (latest)

There is probably a binary/API incompatibility between the older and newer version.

[SbiCA]

• 1 on that and I really feel this should be addressed since at least our team is loosing hours each time we update the combination MSAL, MAUI (.NET) and EF Core due to the the dependency.

Is there any ETA on it because at least on in our case the prevents us from using MSAL on Windows or should we consider alternatives?

[unrateddi]

@SbiCA this ended up been a duplicate of #4933 . The team has responded there so maybe it is best if you follow that issue instead for ETA etc.