@bentraje It's not five GB environment variables, just libraries.
Anyway... Did you put the framework in the right hierarchy? I had to copy the huge thing in several places for the various projects (one for the sample plugins, one for my own, one for the R21 stuff... etc)
This is how my hierarchy looks like:
I got the samples in the newest version from github. The sdk.zip needs to be installed from the C4D installation. (But that's what the original documentation in the other thread says already...)
"Unavailable" sounds as if the framework is not yet installed or cannot be found. If the VisualStudio C++ wouldn't be completely installed, I'd expect compilation errors, but not missing frameworks?