block in activate_dependencies error

[hatemcode]

I got this error when trying to setup rhc:

MacBook-Pro:~ Hatem$ rhc setup
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/specification.rb:1206:in block in activate_dependencies': can't satisfy 'highline (~> 1.6.11)', already activated 'highline-1.7.1' (Gem::LoadError) from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/specification.rb:1198:ineach'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/specification.rb:1198:in activate_dependencies' from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/specification.rb:1180:inactivate'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_gem.rb:48:in gem' from /usr/bin/rhc:22:in

'

What is the problem ?

[hatemcode]

Gust write these line and it is working fine:

gem install rubygems-update
update_rubygems
gem install rhc