ruby - How to resolve LoadError: cannot load such file -- ffi_c -

How do I resolve the next error that appears when executing the requirement command on the console Would you like Installed Ruby 2.2.1 Windows Installer and Ruby Gym 2.4.6 .

  LoadError: Can not load such a file- c from ffi_c: /Ruby22-x64/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_req uire.rb: 54: ` In need ' 

Is this something like DLL?

If you read the documentation for ffi , then you can see:

You need a sensible build environment to compile the extension. At least, you will need:

• AC compiler (for example, GCC on OSX, GCC on everything)
• libffi development library - this is usually Libffi-dev or libffi-devel

This means that the gem is not already compiled, and when it is installed, the code has to be compiled. In return, this means that if you are running on a PC then you have to install Ruby Development Kit for windows, aka "", you can get it from the Ruby Installer site

Download and install first, after that, open a new command-line window:

  Install gem ffi  

For details see: