Ruby on Rails Devise Error: no secure_key

I just installed devise 3.1.1 and whenever I run "rails generate
devise:install" I get an error saying that "Devise.secret_key was not
set. Please add the following to your Devise initializer." I checked in
my "Config/initializers/" folder but there is no "devise.rb" file to
edit! What should I do? please help me, I'm rails beginner and I
searched everywhere but found no solution. thank you.

Hey,

how did you install devise? did you add it to your gem file? run bundle?

all the best,

Andre