ERROR: Failed to build gem native extension on Windows

Question

I\'m getting the below error while installing \'redcarpet\' gem. It got installed without issue on my friends machine though. (I want to install this to run y

Answer 1

Downgrading ruby gems didn't work for me.

What did work was (with the latest version of ruby gems installed):

Open CMD as administrator and...

gem install json --platform=ruby --verbose

(Answer added by dannysmith here)