Completed 406 Not Acceptable in 26.0ms while trying to respond json

i am trying to create an app with angular and rails.as a first step i am trying my controller to give json response , in which i am failing with the below error

Completed 406 Not Acceptable in 26.0ms

my controller-------

class TodosController < ApplicationController   respond_to :json

  def index     #respond_with :@todo     @todo=Todo.all     respond_to do |format|       format.json { render :json => @todo}

  end   end   end

routes.rb------

resources :todos

gemfile--------

source 'https://rubygems.org'

gem 'rails', '3.2.17' gem 'pry-nav'

# Bundle edge Rails instead: # gem 'rails', :git => 'git://github.com/rails/rails.git'

gem 'activerecord-jdbcsqlite3-adapter' gem 'jruby-openssl'

group :development, :test do   gem 'ffaker'   gem 'factory_girl_rails'   gem 'rspec-rails'   gem 'shoulda'   gem 'shoulda-matchers' end

# Gems used only for assets and not required # in production environments by default. group :assets do   gem 'sass-rails', '~> 3.2.3'   gem 'coffee-rails', '~> 3.2.1'

  # See https://github.com/sstephenson/execjs#readme for more supported runtimes   gem 'therubyrhino'

  gem 'uglifier', '>= 1.0.3' end

gem 'jquery-rails'

Copy/paste here the section of development.log leading to the error.

Colin