NoMethodError exception: when trying to access cucumber-2.3.3/ the RDoc (4.2.2)

[timeades]

Error

While processing http://localhost:8808/doc_root/cucumber-2.3.3/ the RDoc (4.2.2) server has encountered a NoMethodError exception:

undefined method `method_list' for nil:NilClass
Did you mean? methods

Please report this to the RDoc issues tracker. Please include the RDoc version, the URI above and exception class, message and backtrace. If you're viewing a gem's documentation, include the gem name and version. If you're viewing Ruby's documentation, include the version of ruby.

Backtrace:

/var/lib/gems/2.3.0/gems/rdoc-4.2.2/lib/rdoc/store.rb:505:in block in load_all' /var/lib/gems/2.3.0/gems/rdoc-4.2.2/lib/rdoc/store.rb:500:ineach'
/var/lib/gems/2.3.0/gems/rdoc-4.2.2/lib/rdoc/store.rb:500:in load_all' /var/lib/gems/2.3.0/gems/rdoc-4.2.2/lib/rdoc/servlet.rb:183:indocumentation_source'
/var/lib/gems/2.3.0/gems/rdoc-4.2.2/lib/rdoc/servlet.rb:386:in show_documentation' /var/lib/gems/2.3.0/gems/rdoc-4.2.2/lib/rdoc/servlet.rb:126:indo_GET'
/usr/lib/ruby/2.3.0/webrick/httpservlet/abstract.rb:107:in service' /usr/lib/ruby/2.3.0/webrick/httpserver.rb:140:inservice'
/usr/lib/ruby/2.3.0/webrick/httpserver.rb:96:in run' /usr/lib/ruby/2.3.0/webrick/server.rb:296:inblock in start_thread'