Can't get project to build after completing Chapter 6 including the example files

[mrhobbeys]

I am stuck on Chapter 6. I can't get the project to build and I just tried downloading the example git and running it with no luck. I have been working through trying to see if it is a NuGet problem or reference problem related somehow, but so far have not made any progress. I just wanted to see if anyone was having similar issues.

It's errors that are very similar to this, however, I reference the right folder of my project. I have even tried deleting the reference and re-adding it.
error: The type or namespace name 'GeoCoords' could not be found (are you missing a using directive or an assembly reference?)

I also have around 100 errors that are something like:
error: The type 'Object' is defined in an assembly that is not referenced. You must add a reference to assembly 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.

I have tried adding references and packages cited for mscorlib, but this had caused more errors and I found people had similar issues and that was not the right direction.