Please verify these steps before filing an issue, and check them off as you go

• The relevant native JavascriptEngineSwitcher library packages are installed (such as JavaScriptEngineSwitcher.V8.Native.win-x64)
• The VC++ 2017 runtime is installed
• The value of SetUseReact and SetUseBabel is correct in ReactConfig.cs or Startup.cs
• I've looked at the sample projects in this repo to verify that my app is configured correctly

I'm using these library versions:

• ReactJS.NET: React.AspNet versions 4.1.1 - 4.2.0-beta1 - 5.0.0-alpha1
• JavaScriptEngineSwitcher: ChakraCore v3.0.9 + win32, win64
• react and react-dom: react 16.8.4 - react-dom 16.8.4
• webpack: N/A
• node: v10.14.1

Runtime environment:

• OS: Windows 10 Eterprise 1803 x64
• .NET Framework or .NET Core Version: .NET Core 3.0 Preview 4

Steps to reproduce

• Start a blank ASP.NET Core 3.0 Preview 4 project
• Follow the getting started guide for aspnet core : https://reactjs.net/getting-started/aspnetcore.html
• When starting the app and loading a script handled by React.NET, loading the script (js/jsx/ts/tsx) end in an unhandled exception.

When loading JSX/TSX using React.NET with ASP.NET Core 3 Preview 4, there's an issue with the BabelFileMiddleware instanciation, since the constructor of the StaticFileMiddleware changed between netcore 2 and netcore 3.

Here's a stack trace :

System.MissingMethodException: Method not found: 'Void Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware..ctor(Microsoft.AspNetCore.Http.RequestDelegate, Microsoft.AspNetCore.Hosting.IHostingEnvironment, Microsoft.Extensions.Options.IOptions`1<Microsoft.AspNetCore.Builder.StaticFileOptions>, Microsoft.Extensions.Logging.ILoggerFactory)'.
at React.AspNet.BabelFileMiddleware.CreateFileMiddleware(IBabel babel)
at React.AspNet.BabelFileMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

Since I need this for validating my computer science degree, I'm interested on contributing on this issue, and help to prepare a release wich is compatible with ASP.NET Core 3. Is there any work in progress for netcore 3 ? And, where can I find the sources for ReactJS.NET 5.0.0-alpha1 ? It seems that master only contains sources for 4.2.0-beta1 (and what's the differences between those two versions ?).