gem install passenger # version 3.0.2

run the command 'passenger start' then I got the error:

c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passenger/plugin.r
b:37:in `load': undefined method `dir' for nil:NilClass (NoMethodError)
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/plugin.rb:34:in `each'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/plugin.rb:34:in `load'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/plugin.rb:72:in `initialize'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/standalone/start_command.rb:52:in `new'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/standalone/start_command.rb:52:in `initialize'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/standalone/main.rb:93:in `new'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/standalone/main.rb:93:in `run_command'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/standalone/main.rb:48:in `each_command'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/standalone/main.rb:43:in `each'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/standalone/main.rb:43:in `each_command'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/standalone/main.rb:91:in `run_command'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/standalone/main.rb:62:in `run!'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/lib/phusion_passe
nger/standalone/main.rb:39:in `run!'
        from c:/Ruby187/lib/ruby/gems/1.8/gems/passenger-3.0.2/bin/passenger:32
        from c:/Ruby187/bin/passenger:19:in `load'
        from c:/Ruby187/bin/passenger:19

Any ideas would be greatly appreciated.