Azure functions dependency injection - error when referencing class library

I have a Azure Functions project that has a reference to a class library (netstandard 2.0). The class library contains a reference to Microsoft.Extensions.DependencyInjection.Abstractions. The class library has the following extension method:

using JOS.MyApp.Core;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

namespace JOS.MyApp.Application
{
    public static class ApplicationConfigurator
    {
        public static void AddApplication(this IServiceCollection services)
        {
              // Do stuff
        }
    }
}

My functions startup looks like this: Startup.cs

using JOS.MyApp.Functions;
using Microsoft.Azure.Functions.Extensions.DependencyInjection;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

[assembly: FunctionsStartup(typeof(Startup))]
namespace JOS.MyApp.Functions
{
    public class Startup : FunctionsStartup
    {
        public override void Configure(IFunctionsHostBuilder builder)
        {
              // It does not matter if this call is here or not, it crashes because of the reference to the class library anyway.
               builder.Services.AddApplication();
        }
    }
}

When the Azure Functions project references the class library, the following error occurs:

Azure Functions Core Tools (2.7.1158 Commit hash: f2d2a2816e038165826c7409c6d10c0527e8955b)
Function Runtime Version: 2.0.12438.0
SKipping 'FUNCTIONS_CORETOOLS_ENVIRONMENT' because value is null
[2019-05-14 20:10:32] Starting Rpc Initialization Service.
[2019-05-14 20:10:32] Initializing RpcServer
[2019-05-14 20:10:32] Building host: startup suppressed:False, configuration suppressed: False
[2019-05-14 20:10:32] A host error has occurred
[2019-05-14 20:10:32] JOS.MyApp.Functions: Method not found: 'Microsoft.Extensions.DependencyInjection.IServiceCollection Microsoft.Azure.Functions.Extensions.DependencyInjection.IFunctionsHostBuilder.get_Services()'.
Value cannot be null.
Parameter name: provider

If I remove the reference to the class library, the function app starts as expected. So the problem appears to be that im using the Microsoft.Extensions.DependencyInjection.Abstractions package in my class library.

To Reproduce

Steps to reproduce the behavior:

1. Create a new functions app
2. Create a new class library
3. Setup DI for your functions app as described here: https://docs.microsoft.com/en-us/azure/azure-functions/functions-dotnet-dependency-injection
4. Add the same extension method as above to the class library
5. Add a reference to the class library from the Azure Functions project
6. Try to run the functions project

Expected behavior

The functions project starts without any issues.

Additional context

Host (useful for support):
  Version: 3.0.0-preview5-27626-15
  Commit:  61f30f5a23

.NET Core SDKs installed:
  2.1.602 [C:\Program Files\dotnet\sdk]
  2.1.700-preview-009597 [C:\Program Files\dotnet\sdk]
  2.1.700-preview-009601 [C:\Program Files\dotnet\sdk]
  2.1.700-preview-009618 [C:\Program Files\dotnet\sdk]
  2.2.202 [C:\Program Files\dotnet\sdk]
  2.2.203 [C:\Program Files\dotnet\sdk]
  2.2.300-preview-010046 [C:\Program Files\dotnet\sdk]
  2.2.300-preview-010050 [C:\Program Files\dotnet\sdk]
  2.2.300-preview-010067 [C:\Program Files\dotnet\sdk]
  3.0.100-preview5-011568 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.9 [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 2.1.9 [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-preview5-19227-01 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.9 [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-preview5-27626-15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.0.0-preview5-27626-15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

[cfe84]

✔️ Had the same issue. Just to clarify how to fix it for anyone who would get that out of the box following the instructions on DI with .net Functions - downgrade version of nuget package Microsoft.Extensions.DependencyInjection from 3.0.0 to 2.2.0

[VaclavElias]

Just a guess, can you mix your class library which is referencing Microsoft.Extensions.DependencyInjection.Abstractions 3.0.0-preview5.19227.9 with Azure Function netcoreapp2.1?