まず、事実：
localhost：3000 / Engageに移動すると、次のエラーが発生します。
ActionController::RoutingError at /
No route matches {:controller=>"engage/home"}
これが私のroutes.rbファイルです：
Kt::Application.routes.draw do
#resources :authentications
resources :paths
mount Engage::Engine => '/engage', :as => 'engage'
resources :comments do
member {post :forresource}
end
resources :resources do
member { post :vote }
collection {get :search}
end
devise_for :users
resources :userResourceView
resources :learningPaths
get "home/index"
devise_scope :user do
get "/login" => "devise/sessions#new"
end
devise_for :user, :path => '', :path_names => {:sign_up => "register" }
match '/user_profile', :to =>'users#index'
get 'tags/:tag', to: 'resources#index', as: :tag
match '/auth/:provider/callback' => 'authentications#create'
match '/auth/:provider/failure', :to => 'authentications#failure'
#match '/auth/:provider/callback?error_reason...', :to => 'profiles#failure'
match '/resources', to: 'resources#create', :via => :post
match 'contact' => 'contact#new', :as => 'contact', :via => :get
match 'contact' => 'contact#create', :as => 'contact', :via => :post
match '/forums' => 'forums#index'
root to: 'home#index', :as => :home
レーキルートを実行すると、次のようになります。
155-99-191-20:KnowledgeThief dainewinters$ rake routes
paths GET /paths(.:format) paths#index
POST /paths(.:format) paths#create
new_path GET /paths/new(.:format) paths#new
edit_path GET /paths/:id/edit(.:format) paths#edit
path GET /paths/:id(.:format) paths#show
PUT /paths/:id(.:format) paths#update
DELETE /paths/:id(.:format) paths#destroy
engage /engage Engage::Engine
forresource_comment POST /comments/:id/forresource(.:format) comments#forresource
comments GET /comments(.:format) comments#index
POST /comments(.:format) comments#create
new_comment GET /comments/new(.:format) comments#new
edit_comment GET /comments/:id/edit(.:format) comments#edit
comment GET /comments/:id(.:format) comments#show
PUT /comments/:id(.:format) comments#update
DELETE /comments/:id(.:format) comments#destroy
vote_resource POST /resources/:id/vote(.:format) resources#vote
search_resources GET /resources/search(.:format) resources#search
resources GET /resources(.:format) resources#index
POST /resources(.:format) resources#create
new_resource GET /resources/new(.:format) resources#new
edit_resource GET /resources/:id/edit(.:format) resources#edit
resource GET /resources/:id(.:format) resources#show
PUT /resources/:id(.:format) resources#update
DELETE /resources/:id(.:format) resources#destroy
new_user_session GET /users/sign_in(.:format) devise/sessions#new
user_session POST /users/sign_in(.:format) devise/sessions#create
destroy_user_session DELETE /users/sign_out(.:format) devise/sessions#destroy
user_password POST /users/password(.:format) devise/passwords#create
new_user_password GET /users/password/new(.:format) devise/passwords#new
edit_user_password GET /users/password/edit(.:format) devise/passwords#edit
PUT /users/password(.:format) devise/passwords#update
cancel_user_registration GET /users/cancel(.:format) devise/registrations#cancel
user_registration POST /users(.:format) devise/registrations#create
new_user_registration GET /users/sign_up(.:format) devise/registrations#new
edit_user_registration GET /users/edit(.:format) devise/registrations#edit
PUT /users(.:format) devise/registrations#update
DELETE /users(.:format) devise/registrations#destroy
userResourceView_index GET /userResourceView(.:format) userResourceView#index
POST /userResourceView(.:format) userResourceView#create
new_userResourceView GET /userResourceView/new(.:format) userResourceView#new
edit_userResourceView GET /userResourceView/:id/edit(.:format) userResourceView#edit
userResourceView GET /userResourceView/:id(.:format) userResourceView#show
PUT /userResourceView/:id(.:format) userResourceView#update
DELETE /userResourceView/:id(.:format) userResourceView#destroy
learningPaths GET /learningPaths(.:format) learningPaths#index
POST /learningPaths(.:format) learningPaths#create
new_learningPath GET /learningPaths/new(.:format) learningPaths#new
edit_learningPath GET /learningPaths/:id/edit(.:format) learningPaths#edit
learningPath GET /learningPaths/:id(.:format) learningPaths#show
PUT /learningPaths/:id(.:format) learningPaths#update
DELETE /learningPaths/:id(.:format) learningPaths#destroy
home_index GET /home/index(.:format) home#index
login GET /login(.:format) devise/sessions#new
new_user_session GET /sign_in(.:format) devise/sessions#new
POST /sign_in(.:format) devise/sessions#create
destroy_user_session DELETE /sign_out(.:format) devise/sessions#destroy
POST /password(.:format) devise/passwords#create
GET /password/new(.:format) devise/passwords#new
GET /password/edit(.:format) devise/passwords#edit
PUT /password(.:format) devise/passwords#update
GET /cancel(.:format) devise/registrations#cancel
POST / devise/registrations#create
GET /register(.:format) devise/registrations#new
GET /edit(.:format) devise/registrations#edit
PUT / devise/registrations#update
DELETE / devise/registrations#destroy
user_profile /user_profile(.:format) users#index
tag GET /tags/:tag(.:format) resources#index
/auth/:provider/callback(.:format) authentications#create
/auth/:provider/failure(.:format) authentications#failure
POST /resources(.:format) resources#create
contact GET /contact(.:format) contact#new
contact POST /contact(.:format) contact#create
forums /forums(.:format) forums#index
home / home#index
Routes for Engage::Engine:
root / engage/topics#index
topic_comments POST /topics/:topic_id/comments(.:format) engage/comments#create
new_topic_comment GET /topics/:topic_id/comments/new(.:format) engage/comments#new
topic_comment DELETE /topics/:topic_id/comments/:id(.:format) engage/comments#destroy
topic_vote GET /topics/:topic_id/vote(.:format) engage/votes#create
POST /topics/:topic_id/vote(.:format) engage/votes#create
DELETE /topics/:topic_id/vote(.:format) engage/votes#destroy
unsubscribe_topic_following GET /topics/:topic_id/following/unsubscribe(.:format) engage/followings#destroy
topic_following GET /topics/:topic_id/following(.:format) engage/followings#create
POST /topics/:topic_id/following(.:format) engage/followings#create
DELETE /topics/:topic_id/following(.:format) engage/followings#destroy
topics GET /topics(.:format) engage/topics#index
POST /topics(.:format) engage/topics#create
new_topic GET /topics/new(.:format) engage/topics#new
edit_topic GET /topics/:id/edit(.:format) engage/topics#edit
topic GET /topics/:id(.:format) engage/topics#show
PUT /topics/:id(.:format) engage/topics#update
DELETE /topics/:id(.:format) engage/topics#destroy
set_intended_action POST /set_intended_action(.:format) engage/application#set_intended_action
user_user_profile PUT /users/:user_id/user_profile(.:format) engage/user_profiles#update
users GET /users(.:format) engage/users#index
また、エラーにはapp / views / shared/_header.html.erbが記載されています。そのファイルは次のとおりです。
<div id="header">
<div id="logoText">
<%= link_to "Knowledge Thief", url_for(:action=>"index", :controller=>"home") %>
</div>
<div class="signin">
<a href="#">
<div class="notifications unread">
3
</div>
</a>
<% unless current_user.nil? %>
<%= link_to "#{current_user.email}", url_for(:action=>"user") %>
<% else %>
<%= link_to "Sign In", url_for(current_user) %>
<% end %>
<%= link_to image_tag("downArrow.png", :style => "height:5px;margin-left:3px;vertical-align:middle;"), url_for(current_user) %>
</div>
</div>
これまでに行った手順（更新予定）：
- 必ずバンドルインストールしてください
- rake db：resetを実行しました
- rake db：migrateを実行しました
- 2日前から現在までの間に何が起こったのかをチームに尋ねました。gitログなどを調べていきます。
これで、/engageがengageにルーティングされていることがわかりますが、この/ homeはどこから来ているのですか？/engageはengage/topics＃indexに行くべきではありませんか？