SwaggerGen service fails in .net core 3

[andre-dasilva]

When running swashbuckle v4.0.1 with .net core 3 an exception occurs while running migrations Reproducing steps:

1. Create .net core 3 application
2. Add Swashbuckle.AspNetCore (=4.0.1) dependency
3. Add-Migration with -verbose

An error occurred while accessing the Microsoft.Extensions.Hosting services. Continuing without the application service provider. Error: Some services are not able to be constructed (Error while validating the service descriptor 'ServiceType: Swashbuckle.AspNetCore.Swagger.ISwaggerProvider Lifetime: Transient ImplementationType: Swashbuckle.AspNetCore.SwaggerGen.SwaggerGenerator': Failed to compare two elements in the array.) (Error while validating the service descriptor 'ServiceType: Swashbuckle.AspNetCore.SwaggerGen.ISchemaRegistryFactory Lifetime: Transient ImplementationType: Swashbuckle.AspNetCore.SwaggerGen.SchemaRegistryFactory': Failed to compare two elements in the array.)

System.AggregateException: Some services are not able to be constructed (Error while validating the service descriptor 'ServiceType: Swashbuckle.AspNetCore.Swagger.ISwaggerProvider Lifetime: Transient ImplementationType: Swashbuckle.AspNetCore.SwaggerGen.SwaggerGenerator': Failed to compare two elements in the array.) (Error while validating the service descriptor 'ServiceType: Swashbuckle.AspNetCore.SwaggerGen.ISchemaRegistryFactory Lifetime: Transient ImplementationType: Swashbuckle.AspNetCore.SwaggerGen.SchemaRegistryFactory': Failed to compare two elements in the array.)
 ---> System.InvalidOperationException: Error while validating the service descriptor 'ServiceType: Swashbuckle.AspNetCore.Swagger.ISwaggerProvider Lifetime: Transient ImplementationType: Swashbuckle.AspNetCore.SwaggerGen.SwaggerGenerator': Failed to compare two elements in the array.
 ---> System.InvalidOperationException: Failed to compare two elements in the array.
 ---> System.TypeLoadException: Could not load type 'Microsoft.AspNetCore.Mvc.MvcJsonOptions' from assembly 'Microsoft.AspNetCore.Mvc.Formatters.Json, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'.
   at System.Signature.GetSignature(Void* pCorSig, Int32 cCorSig, RuntimeFieldHandleInternal fieldHandle, IRuntimeMethodInfo methodHandle, RuntimeType declaringType)
   at System.Reflection.RuntimeConstructorInfo.get_Signature()
   at System.Reflection.RuntimeConstructorInfo.GetParametersNoCopy()
   at System.Reflection.RuntimeConstructorInfo.GetParameters()
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.<>c.<CreateConstructorCallSite>b__16_1(ConstructorInfo a, ConstructorInfo b)
   at System.Collections.Generic.ArraySortHelper`1.SwapIfGreater(T[] keys, Comparison`1 comparer, Int32 a, Int32 b)
   at System.Collections.Generic.ArraySortHelper`1.IntroSort(T[] keys, Int32 lo, Int32 hi, Int32 depthLimit, Comparison`1 comparer)
   at System.Collections.Generic.ArraySortHelper`1.IntrospectiveSort(T[] keys, Int32 left, Int32 length, Comparison`1 comparer)
   at System.Collections.Generic.ArraySortHelper`1.Sort(T[] keys, Int32 index, Int32 length, Comparison`1 comparer)
   --- End of inner exception stack trace ---
   at System.Collections.Generic.ArraySortHelper`1.Sort(T[] keys, Int32 index, Int32 length, Comparison`1 comparer)
   at System.Array.Sort[T](T[] array, Comparison`1 comparison)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateConstructorCallSite(ResultCache lifetime, Type serviceType, Type implementationType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.TryCreateExact(ServiceDescriptor descriptor, Type serviceType, CallSiteChain callSiteChain, Int32 slot)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.TryCreateExact(Type serviceType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateCallSite(Type serviceType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.<>c__DisplayClass7_0.<GetCallSite>b__0(Type type)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.GetCallSite(Type serviceType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateArgumentCallSites(Type serviceType, Type implementationType, CallSiteChain callSiteChain, ParameterInfo[] parameters, Boolean throwIfCallSiteNotFound)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateConstructorCallSite(ResultCache lifetime, Type serviceType, Type implementationType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.TryCreateExact(ServiceDescriptor descriptor, Type serviceType, CallSiteChain callSiteChain, Int32 slot)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.GetCallSite(ServiceDescriptor serviceDescriptor, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.ValidateService(ServiceDescriptor descriptor)
   --- End of inner exception stack trace ---
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.ValidateService(ServiceDescriptor descriptor)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider..ctor(IEnumerable`1 serviceDescriptors, ServiceProviderOptions options)
   --- End of inner exception stack trace ---
   at Microsoft.Extensions.DependencyInjection.ServiceProvider..ctor(IEnumerable`1 serviceDescriptors, ServiceProviderOptions options)
   at Microsoft.Extensions.DependencyInjection.ServiceCollectionContainerBuilderExtensions.BuildServiceProvider(IServiceCollection services, ServiceProviderOptions options)
   at Microsoft.Extensions.DependencyInjection.DefaultServiceProviderFactory.CreateServiceProvider(IServiceCollection containerBuilder)
   at Microsoft.Extensions.Hosting.Internal.ServiceFactoryAdapter`1.CreateServiceProvider(Object containerBuilder)
   at Microsoft.Extensions.Hosting.HostBuilder.CreateServiceProvider()
   at Microsoft.Extensions.Hosting.HostBuilder.Build()
 ---> (Inner Exception #1) System.InvalidOperationException: Error while validating the service descriptor 'ServiceType: Swashbuckle.AspNetCore.SwaggerGen.ISchemaRegistryFactory Lifetime: Transient ImplementationType: Swashbuckle.AspNetCore.SwaggerGen.SchemaRegistryFactory': Failed to compare two elements in the array.
 ---> System.InvalidOperationException: Failed to compare two elements in the array.
 ---> System.TypeLoadException: Could not load type 'Microsoft.AspNetCore.Mvc.MvcJsonOptions' from assembly 'Microsoft.AspNetCore.Mvc.Formatters.Json, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'.
   at System.Signature.GetSignature(Void* pCorSig, Int32 cCorSig, RuntimeFieldHandleInternal fieldHandle, IRuntimeMethodInfo methodHandle, RuntimeType declaringType)
   at System.Reflection.RuntimeConstructorInfo.get_Signature()
   at System.Reflection.RuntimeConstructorInfo.GetParametersNoCopy()
   at System.Reflection.RuntimeConstructorInfo.GetParameters()
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.<>c.<CreateConstructorCallSite>b__16_1(ConstructorInfo a, ConstructorInfo b)
   at System.Collections.Generic.ArraySortHelper`1.SwapIfGreater(T[] keys, Comparison`1 comparer, Int32 a, Int32 b)
   at System.Collections.Generic.ArraySortHelper`1.IntroSort(T[] keys, Int32 lo, Int32 hi, Int32 depthLimit, Comparison`1 comparer)
   at System.Collections.Generic.ArraySortHelper`1.IntrospectiveSort(T[] keys, Int32 left, Int32 length, Comparison`1 comparer)
   at System.Collections.Generic.ArraySortHelper`1.Sort(T[] keys, Int32 index, Int32 length, Comparison`1 comparer)
   --- End of inner exception stack trace ---
   at System.Collections.Generic.ArraySortHelper`1.Sort(T[] keys, Int32 index, Int32 length, Comparison`1 comparer)
   at System.Array.Sort[T](T[] array, Comparison`1 comparison)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateConstructorCallSite(ResultCache lifetime, Type serviceType, Type implementationType, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.TryCreateExact(ServiceDescriptor descriptor, Type serviceType, CallSiteChain callSiteChain, Int32 slot)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.GetCallSite(ServiceDescriptor serviceDescriptor, CallSiteChain callSiteChain)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.ValidateService(ServiceDescriptor descriptor)
   --- End of inner exception stack trace ---
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.ValidateService(ServiceDescriptor descriptor)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider..ctor(IEnumerable`1 serviceDescriptors, ServiceProviderOptions options)<---

[khusroohayat]

You must use at least 5.0.0-rc2 for ASP.NET Core 3.0. Prior versions do not work with ASP.NET Core 3.0.

[andre-dasilva]

Thats what i did in the end. i was just confused because in the README it says that the compatibility for v4.0.1 is .net core >= 2. That should be updated.

[julitogtu]

@khusroohayat do you know what is the estimated date to have the final release of the v5? By some internal policies, i cannot use prerelease versions. Thanks.

[Frankofoedu]

You must use at least 5.0.0-rc2 for ASP.NET Core 3.0. Prior versions do not work with ASP.NET Core 3.0.

This error still exists for a project i am working on running ASP core 3.0 and swashbuckle 5.00-rc4

[vladimirbarov]

This answer helped me: https://github.com/domaindrivendev/Swashbuckle.AspNetCore/issues/1259#issuecomment-557811882. Install Microsoft.OpenApi from nuget.

[romantitov]

For me services.AddControllers(); helped to resolve the issue with Version="5.5.1"

[domaindrivendev]

Closing as readme now reflects the compatability correctly:

Thats what i did in the end. i was just confused because in the README it says that the compatibility for v4.0.1 is .net core >= 2. That should be updated.

[lars-lindstrom]

I'm using .NET Core 5 and Swagger version 5.6.3 and expirenced the same issue. But the feedback of Romantitov did the trick. It was all related to a missing services.AddControllers(); in Startup.cs.

[arsen1us]

This answer helped me: #1259 (comment). Install Microsoft.OpenApi from nuget.

This works on .NET 8