herokuにデプロイした後にThe page you were looking for doesn't exist.

Cloud9で作成したRailsのブログアプリをherokuにデプロイした後に、
投稿（Contact)をお気に入りしようとしたらエラーになってしまいました・・・
Cloud9上では正常に動作します。

The page you were looking for doesn't exist.

ActiveRecord::RecordNotFound (Couldn't find Contact with 'id'=):

該当のソースコード

html
1<div class="container">
2  <div class="row">
3   <div class="col-lg-12">
4
5   <h1>問い合わせ詳細</h1>
6   <div class="col-md-6">
7     <p>件名：<%= @contact.title %></p>
8     <p>内容：<%= @contact.content %></p>
9     <p><%= image_tag @contact.image %></p>
10     
11         <% unless @contact.user_id == current_user.id %>
12             <% if @favorite.present? %>
13　                <% if @favorites.user_id == current_user.id %>
14                       <%= link_to 'お気に入り解除する', favorite_path(id: @favorite.id),
15                       method: :delete, class: 'btn btn-default btn-sm btn btn-danger' %>
16                  <% else %>
17                       <%= link_to 'お気に入りにする', favorites_path(contact_id: @contact.id),
18                       method: :post, class: 'btn btn-default btn-sm btn btn-primary' %>
19                  <% end %>
20             <% else %>
21                <% if @favorites.nil? %>
22                    <%= link_to 'お気に入りにする', favorites_path(contact_id: @contact.id),
23                    method: :post, class: 'btn btn-default btn-sm btn btn-primary' %>
24                <% end %>
25             <% end %>
26        <% end %>
27        
28   
29　　　　
30   </div>
31   <div class="col-md-6">
32     <h3>コメント一覧</h3>
33     <div id="responses_area">
34       <%= render partial: 'responses/index', locals: { responses: @responses, contact: @contact } %>
35     </div>
36       <%= render partial: 'responses/form', locals: { response: @response, contact: @contact } %>
37   </div>
38
39   <div class="col-md-6">
40    <%= link_to "一覧画面にもどる", contacts_path, class: 'btn btn-default btn-sm btn btn-default' %>
41   </div>
42   </div>
43  </div>
44</div>

FavoritesController
1class FavoritesController < ApplicationController
2  def create
3    favorite = current_user.favorites.create(contact_id: params[:contact_id])
4    redirect_to contacts_url, notice: "#{favorite.contact.user.name}さんの投稿をお気に入りしました"
5  end
6
7  def destroy
8    favorite = current_user.favorites.find_by(id: params[:id]).destroy
9    redirect_to contacts_url, notice: "#{favorite.contact.user.name}さんの投稿をお気に入り解除しました"
10  end
11
12  def show
13    @user = User.find(session[:user_id])
14    @favorite_contacts = @user.favorite_contacts
15  end
16  
17
18  #追加
19  def index
20    @user = current_user
21    @favorites = Favorite.where(user_id: @user.id).all
22  end
23
24  def show_favorites
25    @contacts = Contact.find(params[:id])
26    @favorites = Favorite.where(contact_id: @contact.id).all
27  end
28  private
29
30  def contact_params
31    params.require(:contact).permit(:title,:content, :image, :image_cache)
32  end
33end

ContactsController
1class ContactsController < ApplicationController
2  before_action :set_contact, only:[:show, :edit, :update, :destroy]
3  before_action :login_check, only: [:index, :new, :edit, :show, :destroy]
4
5  def index
6    @contacts = Contact.all
7  end
8
9  def new
10    if params[:back]
11      @contact = Contact.new(contact_params)
12    else
13      @contact = Contact.new
14    end
15  end
16
17  def create
18    @contact = Contact.new(contact_params)
19    @contact.user_id = current_user.id
20    if @contact.save
21      #ContactMailer.contact_mail(@contact).deliver
22      redirect_to contacts_path, notice: "問い合わせ中･･･"
23    else
24      render 'new'
25    end
26  end
27
28  def show
29    @contact = Contact.find(params[:id])
30
31    @favorite = current_user.favorites.find_by(contact_id: @contact.id)
32    @favorites = Favorite.find_by(contact_id: @contact.id)
33    
34
35    @responses = @contact.responses.includes(:user).all
36    @response = @contact.responses.build(user_id: current_user.id) if current_user
37  end
38  
39   def edit
40    @contact = Contact.find(params[:id])
41   end
42
43  def update
44    @contact = Contact.find(params[:id])
45    if @contact.update(contact_params)
46      redirect_to contacts_path, notice: "投稿内容を更新しました"
47    else
48      render 'edit'
49    end
50  end
51
52  def destroy
53    @contact.destroy
54    redirect_to contacts_path, notice: "投稿を削除しました"
55  end
56
57  def confirm
58    @contact = Contact.new(contact_params)
59    @contact.user_id = current_user.id
60    render :new if @contact.invalid?
61  end
62
63
64  private
65
66  def contact_params
67    params.require(:contact).permit(:title,:content, :image, :image_cache)
68  end
69
70  def set_contact
71    @contact = Contact.find(params[:id])
72  end
73
74  def login_check
75    unless current_user
76      render new_session_path
77    end
78  end
79end

model
1class Contact < ApplicationRecord
2  validates :title, presence: true, length: {in: 1..500 }
3  validates :content, presence: true, length: {in: 1..500}
4  
5  belongs_to :user
6  has_one :favorite
7  has_many :favorite_users, through: :favorites, source: :user
8  has_many :responses, dependent: :destroy
9 
10  mount_uploader :image, ImageUploader
11end

model
1class User < ApplicationRecord
2  validates :name, presence: true, length: { maximum: 30 }
3  validates :email, presence: true, length: { maximum: 255 },
4            format: { with: /\A[\w+\-.]+@[a-z\d\-.]+.[a-z]+\z/i }
5
6  before_validation { email.downcase! }
7
8  has_secure_password
9  validates :password, presence: true, length: { minimum: 6}
10
11  has_many :contacts
12  has_many :favorites, dependent: :destroy
13  has_many :favorite_contacts, through: :favorites, source: :contact
14
15  has_many :responses
16
17  mount_uploader :icon, IconUploader
18end

route
1Rails.application.routes.draw do
2
3  root to: 'tops#top'
4  resources :contacts do
5    resources :responses
6    collection do
7      post :confirm
8    end
9  end
10
11  resources :contacts do
12    member do
13      get "show_favorites" => "favorites#show_favorites"    
14    end
15  end
16  resources :sessions, only:[:new, :create, :destroy]
17  resources :users
18  resources :favorites, only:[:create, :destroy, :show, :index, :show_favorites]
19
20end

試したこと

rake assets:precompile

<%= link_to 'お気に入りにする', favorites_path(contact_id: @contact.id),
を
<%= link_to 'お気に入りにする', contacts_path(contact_id: @contact.id),
に変えるなどしましたが全くダメでした・・・

もしも情報が不足していたらご指摘ください。