Missing method Exception in the FeatureManagementProvider when upgrading MS Feature Management from 4.0.0 to 4.3.0

[madhon]

Hi, I'm using the following to register the MS Feature Management Provider.

    public static IServiceCollection AddFeatureManagementServices(this IServiceCollection services, IConfiguration configuration)
    {
        services.AddFeatureManagement();

        services.AddOpenFeature(featureBuilder =>
        {
            featureBuilder
                .AddHostedFeatureLifecycle()
                .AddProvider(_ =>
                {
                    var openFeatureManagementProvider = new FeatureManagementProvider(configuration);
                    return openFeatureManagementProvider;
                });
        });

        return services;
    }

This results in the following missing method exception when I upgrade the Microsoft.FeatureManagement.AspNetCore nuget from 4.0.0 to 4.3.0

2025-10-15 11:10:11.006 ERR - Hosting failed to start
System.MissingMethodException: Method not found: 'Void Microsoft.FeatureManagement.ConfigurationFeatureDefinitionProvider..ctor(Microsoft.Extensions.Configuration.IConfiguration)'.
   at OpenFeature.Contrib.Providers.FeatureManagement.FeatureManagementProvider..ctor(IConfiguration configuration, FeatureManagementOptions options)
   at OpenFeature.Contrib.Providers.FeatureManagement.FeatureManagementProvider..ctor(IConfiguration configuration)
   at VehicleRegistrationService.Extensions.FeatureManagementExtensions.<>c__DisplayClass0_0.<AddFeatureManagementServices>b__1(IServiceProvider _) in C:\dev\vehicleregistrationservice\VehicleRegistrationService\Extensions\FeatureManagementExtensions.cs:line 19

The open feature Nuget packages im using are

    <PackageReference Include="OpenFeature" Version="2.8.1" />
    <PackageReference Include="OpenFeature.Contrib.Provider.FeatureManagement" Version="0.1.1-preview" />
    <PackageReference Include="OpenFeature.Hosting" Version="2.8.1" />

[madhon]

Is this provider even maintained anymore or should it be considered DOA given there's been no activity for nearly a year ?

[askpt]

@ericpattison Can you have a look at this one?

[ericpattison]

I should be able to look at it this weekend.