undefined method `id' for nil:NilClass in boxroom_current_user method

[zahid313]

I am using Rails 5.1 and ruby 2.3.1. I have followed readme instructions and set boxroom values in config/initializers/boxroom.rb

Boxroom.configure do |config|
    config.current_user_method = 'current_user' # a method in your application, which returns authenticated User, Boxroom's authentication is disabled
    config.sign_in_path = '/login' # pass string to redirect unauthenticated user to
    config.sign_out_path = '/logout' # pass string to redirect to after sign out, '/dashboard' for example. Or it could be sign out page of you main app
end

but I am getting error when i try to visit http://localhost:3000/boxroom. Error is undefined method `id' for nil:NilClass