Title says it all, here is a sample project to demonstrate my problem.
The assembly you provided is MonoGame 3.4.0, with MonoGame 3.5 code works fine.
I can see that you are right, I installed 3.5 but my template when I make a new project seems to grab 3.4 which is strange. I’m struggling to find the 3.5 install location…
So in C:\Program Files (x86)\MonoGame\v3.0\Assemblies there are a bunch of directories and some of them have 3.4 dll’s and some are 3.5 dlls. Maybe WindowsGL(3.4) got renamed to DesktopGL(3.5) and so they don’t get replaced? This is a very confusing way of organizing the files. Also my templates are still grabbing the 3.4 dlls when I make a new project which is not helping me sort out this confusion.
I uninstalled Monogame and re-installed 3.5 and now the 3.4 folders are all gone and the old 3.4 templates are gone.
Uninstalling and re-installing also fixed an issue that I was having with the content compiler / pipeline tool.