Thread:KockaAdmiralac/@comment-33259544-20180529095742/@comment-27345308-20180530075235

Hmm, I have a feeling this might be because of Cyrillic characters in RubyGems path, could you try reinstalling Ruby into a directory that doesn't contain Cyrillic characters (like  or  )? Also, when asked during installation don't forget to check "Add Ruby executable to PATH".