ruby - First argument in form cannot contain nil or be empty - user sign up form - rails 4 -

i'm trying create basic login/sign form in rails 4 , keep getting error "first argument in form cannot contain nil or empty" @user. part doesn't this:

<%= form_for @user |f| %> 

but have 'new' method in controller, problem people seem have ask error:

class userscontroller < applicationcontroller   def new     @user = user.new   end 

can please help?

addendum: changing <%= form_for user.new do doesn't work either...

your form looking instance of class, in case user in order (i.e. create new 1 or edit existing one). in order allow users register on index page (which wouldn't recommend - breaks restful design) need have in userscontroller

class userscontroller < applicationcontroller   def new     @user = user.new   end    def index     @user = user.new   end