I would help out however, there is no simple way to Emulate a Mac… without hopping through some questionable hoops, and will likely not have a Mac system until 2018 or so… though, you never know what will happen this year…
I think your solution there is the Portable Library method right?
Side note, the reason for the missing files is the File System differences… NTFS C:\... is not possible on a Mac [Well not readily anyway] though you could possibly restructure the file paths to reflect the mac directory structure however I think you already hit the best route…
Though perhaps a better route would be to use the Shared Code route instead… that way you simply copy across the Shared Code/Assets folders between the two and have two dedicated projects instead… makes sense as Windows UI and Mac UI will be different anyway or you can do Conditional compilation though if only targeting two platforms, two individual projects would work best in my opinion…
I hope that helps…
A quick Bing search:
Brought up:
This thread:
And this possibly more useful link:
https://www.codeproject.com/articles/595757/monogame-aplusbuildingplusportableplussolutions
Will add that to the UMGRL thread…
Found this just now:
https://www.codeproject.com/Articles/1129564/MonoGame-Building-Multi-platform-Solutions
In case the YouTube link is not so obvious [Because it isn’t]: