Creating Relationship Error for nil values [solved]

Here is how i got the issue resolved..please note.. I don't knw what all errors are there in the future tutorials as I haven't reached them yet. I set off to fix this one first.  
Also pls note that indentation,new lines,spaces  etc are very imp while writing the codes. Also case sensitivity:
Lets us start step by step:

Step -1: 
a. Add this line to the Gemfile    gem 'protected_attributes'
b. type  bundle install
c. This will install the gem..u can read the specification on their github page if u wish

Step 0: Delete all the statuses and users:
a. Goto rails console by typing: rails console
b. type Status.delete_all
c. u can see all the statuses deleted
d.type User.delete_all
e. u can see all the users deleted as well

Step 1: How your  treebook>app>models>status.rb file should look:

class Status < ActiveRecord::Base
    attr_accessible :content, :user_id
end

Step 2: How your treebook>app>models>user.rb file should look:

class User < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable
  attr_accessible :first_name, :last_name, :profile_name, :email, :password, :password_confirmation
end

Step 3: How your treebook>app>controllers>application_controller.rb file should look:

class ApplicationController < ActionController::Base 

before_filter :configure_permitted_parameters, if: :devise_controller?

protected 
def configure_permitted_parameters 

devise_parameter_sanitizer.for(:sign_up) << :first_name 
devise_parameter_sanitizer.for(:sign_up) << :last_name 
devise_parameter_sanitizer.for(:sign_up) << :profile_name
devise_parameter_sanitizer.for(:sign_up) << :email
devise_parameter_sanitizer.for(:sign_up) << :password
devise_parameter_sanitizer.for(:sign_up) << :password_confirmation
end
protect_from_forgery with: :exception
end

Step 4: Save all the files
Step 5: Start rails server by typing: rails s
Step 6: Go to the web app and register a new user at localhost:3000/user/sign_up
Step 7: Add a new status
Step 8: Stop the server: Ctrl+C
Step 9: Goto rails console: rails console
Step 10: Type user = User.first
Step 11: You can see the new user has been created with all the data filled.
Step 12: Continue with the tutorial Creating relationships and forward.

After this i dont knw wats gonna happen..if other errors come up in later stages..need to research and fix them then!!
the show must go on!! :)