Cloud 9 Rails run time error

I'm developing a simple rails application using cloud 9, every time I run the application I get this error in the cloud 9 browser 'No application seems to be running here!'

To makes things clearer I have researched this and I can't figure out why, I used the following command rails s -b $IP -p $PORT to launch the server, this was done in the root directory of the application. I have installed all the rails gems / bundles needed.

When I do run the app i'm getting a message in the terminal saying 'my code is running at htttps://......... example' when I click the link is when I see the error. Below I will paste the response from the terminal after I try start the server.

$ rails server –b $IP –p $PORT

Exiting
/usr/local/rvm/gems/ruby-2.3.0/gems/rack-1.6.4/lib/rack/handler.rb:78:in `require': cannot load such file -- rack/handler/–b (LoadError)
        from /usr/local/rvm/gems/ruby-2.3.0/gems/rack-1.6.4/lib/rack/handler.rb:78:in `try_require'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/rack-1.6.4/lib/rack/handler.rb:16:in `get'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/rack-1.6.4/lib/rack/server.rb:290:in `server'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/server.rb:125:in `print_boot_information'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/server.rb:75:in `start'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:80:in `block in server'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:75:in `tap'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:75:in `server'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands.rb:17:in `<top (required)>'
        from /home/ubuntu/workspace/dublinapp/bin/rails:9:in `require'
        from /home/ubuntu/workspace/dublinapp/bin/rails:9:in `<top (required)>'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.6.4/lib/spring/client/rails.rb:28:in `load'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.6.4/lib/spring/client/rails.rb:28:in `call'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.6.4/lib/spring/client/command.rb:7:in `call'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.6.4/lib/spring/client.rb:28:in `run'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.6.4/bin/spring:49:in `<top (required)>'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.6.4/lib/spring/binstub.rb:11:in `load'
        from /usr/local/rvm/gems/ruby-2.3.0/gems/spring-1.6.4/lib/spring/binstub.rb:11:in `<top (required)>'
        from /home/ubuntu/workspace/dublinapp/bin/spring:13:in `require'
        from /home/ubuntu/workspace/dublinapp/bin/spring:13:in `<top (required)>'
        from bin/rails:3:in `load'
        from bin/rails:3:in `<main>'