Unable to finish VSCode Tutorial due to build issue

I'm pretty new to Visual Studio code so I am working my way through some of the app tutorials. I am currently unable to progress beyond the Create a Web API with ASP.NET Core MVC page because although the build succeeds, I get a 404 error when I attempt to go to the page. The tutorial says that it should return valid JSON.

I'm kinda lost on this one as I have installed of the dependencies that are required, so I went ahead and installed Visual Studio 2019 Preview and tracked it down to this error:

'ToDoApi.dll' (CLR v4.0.30319: DefaultDomain):

Loaded 'C:\Users\McDeth187\Documents\Projects\Microsoft\Create a Web API\ToDoApi\bin\Debug\netcoreapp2.2\ToDoApi.dll'. Symbols loaded. An unhandled exception of type 'System.IO.FileNotFoundException' occurred in Unknown Module. Could not load file or assembly 'System.Runtime, Version=4.2.1.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.

The program '[8044] ToDoApi.dll: Program Trace' has exited with code 0 (0x0). The program '[8044] ToDoApi.dll' has exited with code -1 (0xffffffff).

I'm unsure where to go from here.