'AuthenticationBuilder' does not contain a definition for 'AddMicrosoftIdentityWebApp'

Question

I'm attempting to add support for Graph into a .Net 6 application. I've previously used Graph in a .Net 5 application but I'm having some trouble understanding how to wire things up using the .Net 6 "simplified" startup.

I've included both:

using Microsoft.Identity.Web;
using Microsoft.Identity.Web.UI;

in the header of Program.cs but I'm getting an error with AddMicrosoftIdentityWebApp in the following:

builder.Services.AddAuthentication(OpenIdConnectDefaults.AuthenticationScheme)
    .AddMicrosoftIdentityWebApp(builder.Configuration.GetSection("AzureAd"))
    .EnableTokenAcquisitionToCallDownstreamApi(initialScopes)
    .AddMicrosoftGraph(builder.Configuration.GetSection("DownstreamApi"))
    .AddInMemoryTokenCaches();

The error I'm getting is:

Error   CS1061  'AuthenticationBuilder' does not contain a definition for 'AddMicrosoftIdentityWebApp' and no accessible extension method 'AddMicrosoftIdentityWebApp' accepting a first argument of type 'AuthenticationBuilder' could be found (are you missing a using directive or an assembly reference?)  

I'm fairly sure that I'm overlooking something pretty simple, but I cannot find it.

Any suggestions are much appreciated.

Answer 1

"Error CS1061 'AuthenticationBuilder' does not contain a definition for 'AddMicrosoftIdentityWebApp' and no accessible extension method 'AddMicrosoftIdentityWebApp' accepting a first argument of type 'AuthenticationBuilder' could be found (are you missing a using directive or an assembly reference?)"

To resolve the above error, please try the below suggestions if helpful:

• When you are including Microsoft.Identity.Web, Microsoft.Identity.Web.UI packages, these libraries are used to simplify the process of signing-in a user and acquiring tokens for Microsoft Graph.

• Try modifying your configured services method by removing the prefix builder like below:

services.AddAuthentication(OpenIdConnectDefaults.AuthenticationScheme)
    .AddMicrosoftIdentityWebApp(Configuration.GetSection("AzureAd"))
    .EnableTokenAcquisitionToCallDownstreamApi(initialScopes)
    .AddMicrosoftGraph(Configuration.GetSection("DownstreamApi"))
    .AddInMemoryTokenCaches();

• To sign-in a user for your application with Microsoft identity platform endpoint AddMicrosoftIdentityWebApp() is used.

• EnableTokenAcquisitionToCallDownstreamApi() and AddMicrosoftGraph adds support to call Microsoft Graph.

• Otherwise, If you want to use builder, make sure to add the package using Microsoft.AspNetCore.Identity and define the builder as below:

var builder = WebApplication.CreateBuilder(args);

For more in detail, please refer below links:

active-directory-aspnetcore-webapp-openidconnect-v2/README.md at master · Azure-Samples/active-directory-aspnetcore-webapp-openidconnect-v2 · GitHub.

Configure ASP.NET Core Identity | Microsoft Docs.

Answer 2

Thanks for the response.

As it turns out, I found that the problem was with an incorrect package being installed. I had included Decos.Microsoft.Indentity.Web in the packages for the solution. I suspect that there were some collisions occurring here. Once I removed the package the error no longer manifests itself.