I'm using Ubuntu 18.04.4 LTS and I went through the instructions on this page: https://www.monodevelop.com/download/ very specifically, (yes, I made sure to use the steps for the correct operating system, and I did all of the steps at the bottom, I have all certificates and performed all fo the updates).
I then opened monodevelop and went into tools and downloaded the monogame extension.
Then I was able to create a new solution of type MonoGame... the options are: Cross Platform, iPhone/iPad, Android, Windows, Mac, and tvOS. Apparently there isn't even support for Android at all so I don't know why that's even an option. I then tried Cross Platform, and am now trying Windows Application... And when a make a solution for either of these files and just try to build the initial boiler plate code that they give me, I get the following error as demonstrated in the image below. Does anyone know how to get these assemblies? And why are all of these files missing? I deleted Monodevelop from my machine and reinstalled it from scratch and tried again using a new solution and it's all the same. Is game development for MonoGame using MonoDevelop on a Linux machine even possible?