C5 Generic Collection Library Does Not Compile on iOS with micro mscorlib

I was wondering if anyone here was able to get the C5 Generic Collection Library able to compile with their code when building to an iOS device while using the micro mscorlib?

Whenever we build to the device we get this error in Unity:

First we tried with the dll, then we included the C5 cs files in our project as well, but we still get the error.

Are there .Net limits on what you can and cannot call from monodevelop on iOS, or is this another issue?

Maybe it’s the version of the dll you’re using?

I don’t think it matters. I tried every version available, I still get the same error.