The type or namespace name 'Platforms' does not exist in the namespace 'Auth0.OidcClient' (are you missing an assembly reference?)

[AdalbertKhoolsaat]

Checklist

• I have looked into the Readme and the documentation, and have not found a suitable solution or answer.
• I have looked into the API documentation and have not found a suitable solution or answer.
• I have searched the issues and have not found a suitable solution or answer.
• I have searched the Auth0 Community forums and have not found a suitable solution or answer.
• I agree to the terms within the Auth0 Code of Conduct.

Description

Created a .NET MAUI App using the Auth0 .NET MAUI App Template (version 2.3.1).

Auth0.OidcClient.MAUI version is 1.4.0.

The resulting project comes with a persistent build error stemming from this line in App.xaml.cs:

        if (!Auth0.OidcClient.Platforms.Windows.Activator.Default.CheckRedirectionActivation())
            InitializeComponent();

Error as in the title of this issue:
The type or namespace name 'Platforms' does not exist in the namespace 'Auth0.OidcClient' (are you missing an assembly reference?)

The only similar issue I could find was this one:
https://community.auth0.com/t/platforms-namespace-gone/181693/6

But I have no luck when trying the suggested solution of changing the Windows target framework, the project simply won't build for any platform.

Reproduction

1. Create a project using the Auth0 .NET MAUI App Template (version 2.3.1).
2. Target .NET 9.
3. That's it.

Additional context

Using Visual Studio Version 17.14.15.
When debugging on Windows Machine, it WILL build and run for both versions despite the error being present at compile time.

For Android it will simply fail to build.

auth0-oidc-client-net version

maui-1.4.0

.NET version

9

Platform

Windows, Android

Platform version(s)

net9.0-android ; net9.0-windows10.0.20348.0 ; net9.0-windows10.0.19041.0

[kailash-b]

Hi @AdalbertKhoolsaat 👋
Thanks for taking time to report this.

The build error happens because Auth0.OidcClient.Platforms.Windows.Activator.Default.CheckRedirectionActivation() is only available for Windows targets—it’s defined in a Windows-specific directory and isn’t present when building for Android or other platforms. The template refers to this code from the shared App.xaml.cs, since the namespace and type don’t exist in Android, the build fails.

To fix this, wrap the Windows-specific code in a preprocessor directive so it only compiles for Windows:

#if WINDOWS
if (Auth0.OidcClient.Platforms.Windows.Activator.Default.CheckRedirectionActivation())
    return;
#endif

InitializeComponent();

OR move this if condition out of this file and place it in the App.xaml.cs file that is under the Windows-specific folder
This ensures the method is only called when building for Windows, resolving the error for Android and other platforms.

In the meantime, we will work to improve our documentation by explicitly calling this out and by updating the template code.

Hope this helps! Do reach out if there's anything more needed.