undefined local variable or method `config' for main:Object - rails

Question

When I run the rails application, I get the following error:

undefined local variable or method \"config\" for main:Object

How c

Answer 1

I had this problem when an application had been upgraded from Rails 2 to Rails 3. It worked in development but I got this error when running in production mode for the first time because config/environments/production.rb contained Rails 2-style lines such as:

config.cache_classes = true

..which needed converting to Rails 3-style:

<>::Application.configure do

  config.cache_classes = true
end