インクリメンタルサーチ406 (Not Acceptable)で困っています

https://gyazo.com/7b8270fe0a211e882b17b38f807bf901

searchjsonjbuilder
1json.array! @posts do |post|
2  json.id post.id
3  json.title post.title
4  json.video post.video
5  json.user_id post.user_id
6  json.nickname post.user.nickname
7  json.user_sign_in current_user
8end

rails
1class PostsController < ApplicationController
2  before_action :set_post, only:[:edit,:show]
3  before_action :move_to_index, except: [:index, :show, :search]
4  def index
5    @posts = Post.includes(:user).order("created_at DESC")
6  end
7  def new
8    @post = Post.new
9  end
10  def create
11    if Post.create(post_params)
12      redirect_to  "/users/#{current_user.id}", notice: '投稿が完了しました'
13    else
14      render :new
15    end
16  end
17  def destroy
18    post=Post.find(params[:id])
19    if post.destroy
20      redirect_to "/users/#{current_user.id}", notice: '削除が完了しました'
21    else
22      render :destroy
23    end
24  end
25  def edit
26  end
27  def update
28    post  = Post.find(params[:id])
29    if post.update(post_params)
30      redirect_to "/users/#{current_user.id}", notice: '編集が完了しました'
31    else
32      render :edit
33    end
34  end
35  def show
36    @comment=Comment.new
37    @comments = @post.comments.includes(:user)
38  end
39  def search
40    @posts = Post.search(params[:keyword])
41    respond_to do |format|
42      format.html
43      format.json
44    end
45  end
46
47  private
48  def post_params
49    params.require(:post).permit(:title,:video,:text).merge(user_id: current_user.id)
50  end
51  def set_post
52    @post=Post.find(params[:id])
53  end
54  def move_to_index
55    redirect_to action: :index unless user_signed_in?
56  end
57end

js
1$(function(){
2  $(".search-input").on("keyup", function(){
3    var input = $(".search-input").val();
4    $.ajax({
5      type: 'GET',
6      url: '/posts/search',
7      data: { keyword: input },
8      dataType: 'json'
9    })
10    .done(function(post) {
11      console.log(post)
12    })
13  });
14});