The runtime version supported by this application is unavailable.

I did some research on how to solve this and found some posts that say you need to add this:

runtime=v4.0.30319

to the program.exe.config file, but I don't seem to have a config file and these notes were written for Mono, not Mono for Android (I believe).

Does anyone know where I am supposed to add this directive? And if it is the correct thing to do in Visual Studio and Mono? I am using a library of C# code within my project.

Thanks!