Swashbuckle.AspNetCore.Annotations in AspNetCore 3.0-preview4 gives error

[tomgron]

After adding Swashbuckle.AspNetCore.Annotations 4.0.1 to newly created ASP.NET Core 3 Preview 4 project I get exception of :

  | Name | Value | Type
-- | -- | -- | --
◢ | $exception | {"Unable to load one or more of the requested types.rnMethod 'Apply' in type 'Swashbuckle.AspNetCore.Annotations.AnnotationsDocumentFilter' from assembly 'Swashbuckle.AspNetCore.Annotations, Version=4.0.1.0, Culture=neutral, PublicKeyToken=e9121ecc40036af8' does not have an implementation.rnMethod 'Apply' in type 'Swashbuckle.AspNetCore.Annotations.AnnotationsOperationFilter' from assembly 'Swashbuckle.AspNetCore.Annotations, Version=4.0.1.0, Culture=neutral, PublicKeyToken=e9121ecc40036af8' does not have an implementation.rnMethod 'Apply' in type 'Swashbuckle.AspNetCore.Annotations.AnnotationsParameterFilter' from assembly 'Swashbuckle.AspNetCore.Annotations, Version=4.0.1.0, Culture=neutral, PublicKeyToken=e9121ecc40036af8' does not have an implementation.rnMethod 'Apply' in type 'Swashbuckle.AspNetCore.Annotations.AnnotationsSchemaFilter' from assembly 'Swashbuckle.AspNetCore.Annotations, Version=4.0.1.0, Culture=neutral, PublicKeyToken=e9121ecc40036af8' does not have an implementation."} | System.Reflection.ReflectionTypeLoadException

Dotnet --info:

.NET Core SDK (reflecting any global.json):
 Version:   3.0.100-preview4-011223
 Commit:    118dd862c8

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.17763
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\3.0.100-preview4-011223\

Host (useful for support):
  Version: 3.0.0-preview4-27615-11
  Commit:  ee54d4cbd2

.NET Core SDKs installed:
  2.1.600-preview-009497 [C:\Program Files\dotnet\sdk]
  2.1.600 [C:\Program Files\dotnet\sdk]
  2.1.601 [C:\Program Files\dotnet\sdk]
  2.1.602 [C:\Program Files\dotnet\sdk]
  2.2.104 [C:\Program Files\dotnet\sdk]
  2.2.105 [C:\Program Files\dotnet\sdk]
  2.2.200-preview-009804 [C:\Program Files\dotnet\sdk]
  2.2.200 [C:\Program Files\dotnet\sdk]
  2.2.201 [C:\Program Files\dotnet\sdk]
  2.2.202 [C:\Program Files\dotnet\sdk]
  2.2.203 [C:\Program Files\dotnet\sdk]
  3.0.100-preview4-011223 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.2.1 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.2.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.2.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.2.4 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.2.1 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.2.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.2.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.2.4 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.0.0-preview4-19216-03 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.2.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.2.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.2.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.2.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.0.0-preview4-27615-11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.0.0-preview4-27613-28 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET Core runtimes or SDKs:
  https://aka.ms/dotnet-download

Startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Swashbuckle.AspNetCore.SwaggerUI;

namespace api
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers()
                .AddNewtonsoftJson();
            services.AddSwaggerGen(options =>
            {
                //options.EnableAnnotations();
            });
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }

            app.UseHttpsRedirection();

            app.UseSwagger();

            app.UseSwaggerUI();

            app.UseRouting();

            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }
}

.csproj

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>netcoreapp3.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.0.0-preview4-19216-03" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="3.0.0-preview4.19216.3" />
    <PackageReference Include="Serilog.AspNetCore" Version="2.1.2-dev-00028" />
    <PackageReference Include="Serilog.Sinks.Console" Version="3.1.2-dev-00792" />
    <PackageReference Include="Swashbuckle.AspNetCore" Version="5.0.0-rc2" />
    <PackageReference Include="Swashbuckle.AspNetCore.Annotations" Version="4.0.1" />
    <PackageReference Include="Swashbuckle.AspNetCore.Swagger" Version="5.0.0-rc2" />
    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerGen" Version="5.0.0-rc2" />
    <PackageReference Include="Swashbuckle.AspNetCore.SwaggerUI" Version="5.0.0-rc2" />
  </ItemGroup>

</Project>

[domaindrivendev]

Why are you using an older version of the Annotations package. I don't think this will work as it's not compatible with the other SB packages. If you update to 5.0.0-rc2 it should work fine.

[microgold]

This helped me thanks. Yes, for swagger to work properly, all the swashbuckle.aspnetcore versions must match to 5.0.0