GetFallbackPolicyAsync does not have an implementation

Using dotnet core version 3 (Preview 7) results in the error

System.Reflection.ReflectionTypeLoadException: 'Unable to load one or more of the requested types.
Method 'GetFallbackPolicyAsync' in type 'Google.Apis.Auth.AspNetCore.GoogleScopedPolicyProvider' from assembly 'Google.Apis.Auth.AspNetCore, Version=1.40.2.0, Culture=neutral, PublicKeyToken=4b01fa6e34db77ab' does not have an implementation.'

What I am trying to do is pull back blog posts first, and then I want to integrate with some other APIs. I do have the latest Google.Apis libraries from NuGet. It was working with 3.0 Preview 5, but ASP.NET core has a new @code that is replacing @function in razor pages.

The full trace is

   at System.Reflection.RuntimeModule.GetTypes(RuntimeModule module)
   at System.Reflection.RuntimeAssembly.get_DefinedTypes()
   at Microsoft.AspNetCore.Mvc.ApplicationParts.AssemblyPart.get_Types()
   at Microsoft.AspNetCore.Mvc.Controllers.ControllerFeatureProvider.PopulateFeature(IEnumerable`1 parts, ControllerFeature feature)
   at Microsoft.AspNetCore.Mvc.ApplicationParts.ApplicationPartManager.PopulateFeature[TFeature](TFeature feature)
   at Microsoft.AspNetCore.Mvc.ApplicationModels.ControllerActionDescriptorProvider.GetControllerTypes()
   at Microsoft.AspNetCore.Mvc.ApplicationModels.ControllerActionDescriptorProvider.GetDescriptors()
   at Microsoft.AspNetCore.Mvc.ApplicationModels.ControllerActionDescriptorProvider.OnProvidersExecuting(ActionDescriptorProviderContext context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.DefaultActionDescriptorCollectionProvider.UpdateCollection()
   at Microsoft.AspNetCore.Mvc.Infrastructure.DefaultActionDescriptorCollectionProvider.Initialize()
   at Microsoft.AspNetCore.Mvc.Infrastructure.DefaultActionDescriptorCollectionProvider.GetChangeToken()
   at Microsoft.AspNetCore.Mvc.Routing.ActionEndpointDataSourceBase.<>c__DisplayClass11_0.<Subscribe>b__0()
   at Microsoft.Extensions.Primitives.ChangeToken.ChangeTokenRegistration`1..ctor(Func`1 changeTokenProducer, Action`1 changeTokenConsumer, TState state)
   at Microsoft.Extensions.Primitives.ChangeToken.OnChange(Func`1 changeTokenProducer, Action changeTokenConsumer)
   at Microsoft.AspNetCore.Mvc.Routing.ActionEndpointDataSourceBase.Subscribe()
   at Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure.PageActionEndpointDataSource..ctor(IActionDescriptorCollectionProvider actions, ActionEndpointFactory endpointFactory)
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, RuntimeResolverContext context)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSiteMain(ServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitCache(ServiceCallSite callSite, RuntimeResolverContext context, ServiceProviderEngineScope serviceProviderEngine, RuntimeResolverLock lockType)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitRootCache(ServiceCallSite singletonCallSite, RuntimeResolverContext context)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(ServiceCallSite callSite, TArgument argument)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite, ServiceProviderEngineScope scope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__0(ServiceProviderEngineScope scope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType)
   at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetService[T](IServiceProvider provider)
   at Microsoft.AspNetCore.Builder.RazorPagesEndpointRouteBuilderExtensions.EnsureRazorPagesServices(IEndpointRouteBuilder endpoints)
   at Microsoft.AspNetCore.Builder.RazorPagesEndpointRouteBuilderExtensions.MapFallbackToPage(IEndpointRouteBuilder endpoints, String page)

[elutsky]

@chrisdunelm Any updates on this? we are pretty blocked with .net core 3.0 migrations, and .net core 2.2 is touching the “End Of Life” in 2 weeks (23/12/19)

[jskeet]

@jmmccota: Yes, as per the previous comments, use the new Google.Apis.Auth.AspNetCore3 package.