undefined method `acceptable?'

[suchakra]

Failure/Error: agent.cookie_jar.load("cookies.yaml")

 NoMethodError:
   undefined method `acceptable?' for #<Hash:0x007f9b4220cf30>
 # /Users/UsEr/.rvm/gems/ruby-2.3.0@osso/gems/http-cookie-1.0.3/lib/http/cookie_jar.rb:108:in `add'
 # /Users/UsEr/.rvm/gems/ruby-2.3.0@osso/gems/mechanize-2.7.5/lib/mechanize/cookie_jar.rb:22:in `add'

...