UseBootstrapFileProvider throws NullReferenceException about unleash-client-dotnet HOT 4 CLOSED

    internal class UnleashSettingsInitializeFeaturesConfigurator : IConfigureOptions<UnleashSettings>
    {
        private readonly IConfiguration _configuration;
        private readonly UnleashOptions _unleashOptions;

        public UnleashSettingsInitializeFeaturesConfigurator(IConfiguration configuration, IOptions<UnleashOptions> unleashOptions)
        {
            _configuration = configuration;
            _unleashOptions = unleashOptions.Value;
        }

        public void Configure(UnleashSettings options)
        {
            var enableFeaturesInitialization = _configuration.GetValue("INITIALIZE_FEATURETOGGLE", false);

            if (enableFeaturesInitialization)
            {
                var fileSystemType = Type.GetType("Unleash.Internal.FileSystem, Unleash.Client");
                var fileSystemObj = Activator.CreateInstance(fileSystemType!, Encoding.UTF8)!;

                var systemFileProp = options.GetType().GetProperty("FileSystem", BindingFlags.Instance | BindingFlags.NonPublic)!;
                systemFileProp.SetValue(options, fileSystemObj);

                options.UseBootstrapFileProvider("features.json");
            }
        }
    }