Csharp 为什么我点击登录按钮时，我的服务Provider Web应用程序会抛出此错误

我正在构建一个.Net Core Web App，它将成为一个服务Provider ，并使用SSO通过身份Provider 登录用户.

当我加载Web应用程序并单击Login时...我收到错误...

我的appsettings.json档案中有以下内容:

  "Saml2": {
    "zau_idpMetadata": "https://saml.zau.edu/zau_idp/shibboleth ",
    "Issuer": "UniversityComms",
    "SingleSignOnDestination": "https://saml.zau.edu/zau_idp/profile/SSO",
    "SingleLogoutDestination": "https://saml.zau.edu/zau_idp/profile/Logout",
    "CertificateValidationMode": "None",
    //"CertificateValidationMode": "ChainTrust",
    "RevocationMode": "NoCheck"
  }

你可以看到我定义了SingleLogoutDestination个.

这是在我的program.cs文件中:

builder.Services.Configure<Saml2Configuration>(saml2Configuration =>
{
    saml2Configuration.AllowedAudienceUris.Add(saml2Configuration.Issuer);

    var entityDescriptor = new EntityDescriptor();
    //entityDescriptor.ReadIdPSsoDescriptorFromUrlAsync(httpClientFactory, new Uri(Configuration["Saml2:IdPMetadata"])).GetAwaiter().GetResult();
    entityDescriptor.ReadIdPSsoDescriptorFromUrl(new Uri(configuration["Saml2:IdPMetadata"]));
    if (entityDescriptor.IdPSsoDescriptor != null)
    {
        saml2Configuration.SingleSignOnDestination = entityDescriptor.IdPSsoDescriptor.SingleSignOnServices.First().Location;
        saml2Configuration.SingleLogoutDestination = entityDescriptor.IdPSsoDescriptor.SingleLogoutServices.First().Location;
        saml2Configuration.SignatureValidationCertificates.AddRange(entityDescriptor.IdPSsoDescriptor.SigningCertificates);
    }
    else
    {
        throw new Exception("IdPSsoDescriptor not loaded from metadata.");
    }
});

builder.Services.AddSaml2();

var app = builder.Build();

然而，当我启动应用程序，并try 通过SSO登录时，我收到以下错误:

System.InvalidOperationException:‘Sequence Not Elements’

以下是完整的错误:

  InvalidOperationException: Sequence contains no elements

    System.Linq.ThrowHelper.ThrowNoElementsException()
    System.Linq.Enumerable.First<TSource>(IEnumerable<TSource> source)
    Program+<>c__DisplayClass0_0.<<Main>$>b__0(Saml2Configuration saml2Configuration) in Program.cs

        var entityDescriptor = new EntityDescriptor();
        //entityDescriptor.ReadIdPSsoDescriptorFromUrlAsync(httpClientFactory, new Uri(Configuration["Saml2:IdPMetadata"])).GetAwaiter().GetResult();
        entityDescriptor.ReadIdPSsoDescriptorFromUrl(new Uri(configuration["Saml2:IdPMetadata"]));
        if (entityDescriptor.IdPSsoDescriptor != null)
        {
            saml2Configuration.SingleSignOnDestination = entityDescriptor.IdPSsoDescriptor.SingleSignOnServices.First().Location;

            saml2Configuration.SingleLogoutDestination = entityDescriptor.IdPSsoDescriptor.SingleLogoutServices.First().Location;

            saml2Configuration.SignatureValidationCertificates.AddRange(entityDescriptor.IdPSsoDescriptor.SigningCertificates);
        }
        else
        {
            throw new Exception("IdPSsoDescriptor not loaded from metadata.");
        }

Microsoft.Extensions.Options.OptionsFactory<TOptions>.Create(string name)
Microsoft.Extensions.Options.UnnamedOptionsManager<TOptions>.get_Value()
UniversityComms.Controllers.AuthController..ctor(IOptions<Saml2Configuration> configAccessor) in AuthController.cs

        {
            const string relayStateReturnUrl = "ReturnUrl";
            private readonly Saml2Configuration config;
            public AuthController(IOptions<Saml2Configuration> configAccessor)
            {

                config = configAccessor.Value;

            }
            [Route("Login")]
            public IActionResult Login(string? returnUrl = null)
            {
                var binding = new Saml2RedirectBinding();

lambda_method22(Closure , IServiceProvider , object[] )