undefined method `save' for nil:NilClass - ruby-on-rails

Question

I get this error when trying to register a new user.
NoMethodError (undefined method save' for nil:NilClass):
app/controllers/users_controller.rb:49:increate'
app/controllers/users_controller.rb:48:in `create'
class UsersController < ApplicationController
before_filter :require_no_user, :only => [:new, :create]
before_filter :require_user, :only => [:show, :edit, :update]
#filter_resource_access
def index
#users = User.all
respond_to do |format|
format.html # index.html.erb
format.xml { render :xml => #users }
end
end
def show
respond_to do |format|
format.html # show.html.erb
format.xml { render :xml => #user }
end
end
def new
##user = User.new
#carriers = Carrier.find(:all)
respond_to do |format|
format.html # new.html.erb
format.xml { render :xml => #user }
end
end
def edit
end
def create
#user = User.new(params[:user])
if #user.save
flash[:notice] = "Account registered!"
redirect_back_or_default account_url
else
render :action => :new
end
end
def profile
#user = User.find(params[:id])
end
def update
respond_to do |format|
if #user.update_attributes(params[:user])
format.html { redirect_to(#user, :notice => 'User was successfully updated.') }
format.xml { head :ok }
else
format.html { render :action => "edit" }
format.xml { render :xml => #user.errors, :status => :unprocessable_entity }
end
end
end
def destroy
#user = User.find(params[:id])
#user.destroy
respond_to do |format|
format.html { redirect_to(users_url) }
format.xml { head :ok }
end
end
def delete
#user = User.find(params[:user_id])
#user.destroy
redirect_to :users
end
end

Answer 1

without seeing your view code, its hard to say, but since you have commented out the #user object that is sent to the new view, perhaps the params coming back from the view are not defined as key value pairs from the form as user attributes?

Answer 2

The error is happening because the #user variable is nil, so calling (nil).save will fail. This means that User.new(params[:user]) is returning nil, which should never happen. User.new should always return a record, even if it is invalid.
So, since the controller looks pretty ordinary, I'll take a shot in the dark and suggest checking your User model for a 'new' method. You might be overriding ActiveRecord's 'new' method with some logic that returns nil and breaks your controller. If so, you must replace 'def new' with a different method name.
If that doesn't help, please provide us with the code in your User model.