Mongoid 3.0.0 Moped Errors and Undefined Method :Nill

[roopesh jupudi]

plz solve my problem

used ruby 1.9.3
rails 3.2.1
mongoid 3.0.0

create a sample application

rails g scaffold article name:string content:text

but getting error in index page ,cannot create an article getting error
undefine method for nill class 

[roopesh jupudi]

Solved my error ..its my mistake ..my ruby version is in 1.9.2
just changed to 1.9.3 it worked