更新通过在routes.rb到config.sign_out_via = :delete进行一次换行，修复了退出问题。据我所知，这允许用户使用HTTP删除方法注销。我真的不明白的是create new post功能在此更改后的工作原理。如果有人能够解释这一点，我将非常感激。
更新：我应该提到我的生产数据库是最新的，heroku运行rake db：migrate是我在google搜索时遇到的第一个解决方案，但还没有解决我的问题。
此外，我使用AWS S3存储以前工作正常的图像，直到我添加了我的设计功能
相关应用程序托管在我的GitHub here
上我的图片分享应用程序在我的开发环境中使用sqlite完美运行。在生产中（在Heroku上）我使用的是postgres。我想这个问题与使用Devise和Postgres有关。
当我尝试在http://imgfall.herokuapp.com/posts/new创建新帖子或在http://imgfall.herokuapp.com/users/sign_out签名后退出时，会出现问题。
注销链接只显示标准的Rails错误页面The page you were looking for doesn't exist.这似乎是路由问题，但我不知道解决方案。我的生产路线似乎与开发相同，所以不应该有问题（对吧？）
我检查了heroku日志，其中显示了与创建新帖子相关的以下错误：
Started GET "/posts/new" for 174.102.98.169 at 2015-08-15 16:19:47 +0000
Completed 500 Internal Server Error in 8ms
Processing by PostsController#new as HTML
ActiveRecord::UnknownAttributeError (unknown attribute: user_id):
app/controllers/posts_controller.rb:31:in `new'
Processing by PostsController#new as HTML
ActiveRecord::UnknownAttributeError (unknown attribute: user_id):
app/controllers/posts_controller.rb:31:in `new'
Started GET "/posts/new" for 174.102.98.169 at 2015-08-15 16:19:47 +0000
Completed 500 Internal Server Error in 3ms
以及与注销相关的以下错误：
Started DELETE "/users/sign_out" for 174.102.98.169 at 2015-08-15 16:21:19 +0000
ActionController::RoutingError (No route matches [DELETE] "/users/sign_out"):
vendor/bundle/ruby/2.0.0/gems/actionpack-4.1.8/lib/action_dispatch/middleware/debug_exceptions.rb:21:in `call'
vendor/bundle/ruby/2.0.0/gems/actionpack-4.1.8/lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
vendor/bundle/ruby/2.0.0/gems/railties-4.1.8/lib/rails/rack/logger.rb:38:in `call_app'
vendor/bundle/ruby/2.0.0/gems/railties-4.1.8/lib/rails/rack/logger.rb:20:in `block in call'
vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/tagged_logging.rb:68:in `block in tagged'
vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/tagged_logging.rb:26:in `tagged'
vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/tagged_logging.rb:68:in `tagged'
vendor/bundle/ruby/2.0.0/gems/railties-4.1.8/lib/rails/rack/logger.rb:20:in `call'
vendor/bundle/ruby/2.0.0/gems/actionpack-4.1.8/lib/action_dispatch/middleware/request_id.rb:21:in `call'
vendor/bundle/ruby/2.0.0/gems/rack-1.5.5/lib/rack/methodoverride.rb:21:in `call'
vendor/bundle/ruby/2.0.0/gems/rack-1.5.5/lib/rack/runtime.rb:17:in `call'
vendor/bundle/ruby/2.0.0/gems/activesupport-4.1.8/lib/active_support/cache/strategy/local_cache_middleware.rb:26:in `call'
vendor/bundle/ruby/2.0.0/gems/actionpack-4.1.8/lib/action_dispatch/middleware/static.rb:84:in `call'
vendor/bundle/ruby/2.0.0/gems/rack-1.5.5/lib/rack/sendfile.rb:112:in `call'
vendor/bundle/ruby/2.0.0/gems/railties-4.1.8/lib/rails/engine.rb:514:in `call'
vendor/bundle/ruby/2.0.0/gems/railties-4.1.8/lib/rails/application.rb:144:in `call'
vendor/bundle/ruby/2.0.0/gems/rack-1.5.5/lib/rack/lock.rb:17:in `call'
vendor/bundle/ruby/2.0.0/gems/rack-1.5.5/lib/rack/content_length.rb:14:in `call'
vendor/bundle/ruby/2.0.0/gems/rack-1.5.5/lib/rack/handler/webrick.rb:60:in `service'
vendor/ruby-2.0.0/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
vendor/ruby-2.0.0/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
vendor/ruby-2.0.0/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'
当我运行Heroku run rake routes时，我得到：
Running `rake routes` attached to terminal... up, run.9186
Prefix Verb URI Pattern Controller#Action
new_user_session GET /users/sign_in(.:format) devise/sessions#new
user_session POST /users/sign_in(.:format) devise/sessions#create
destroy_user_session GET /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
PATCH /users/password(.:format) devise/passwords#update
PUT /users/password(.:format) devise/passwords#update
cancel_user_registration GET /users/cancel(.:format) registrations#cancel
user_registration POST /users(.:format) registrations#create
new_user_registration GET /users/sign_up(.:format) registrations#new
edit_user_registration GET /users/edit(.:format) registrations#edit
PATCH /users(.:format) registrations#update
PUT /users(.:format) registrations#update
DELETE /users(.:format) registrations#destroy
post_comments GET /posts/:post_id/comments(.:format) comments#index
POST /posts/:post_id/comments(.:format) comments#create
new_post_comment GET /posts/:post_id/comments/new(.:format) comments#new
edit_post_comment GET /posts/:post_id/comments/:id/edit(.:format) comments#edit
post_comment GET /posts/:post_id/comments/:id(.:format) comments#show
PATCH /posts/:post_id/comments/:id(.:format) comments#update
PUT /posts/:post_id/comments/:id(.:format) comments#update
DELETE /posts/:post_id/comments/:id(.:format) comments#destroy
posts GET /posts(.:format) posts#index
POST /posts(.:format) posts#create
new_post GET /posts/new(.:format) posts#new
edit_post GET /posts/:id/edit(.:format) posts#edit
post GET /posts/:id(.:format) posts#show
PATCH /posts/:id(.:format) posts#update
PUT /posts/:id(.:format) posts#update
DELETE /posts/:id(.:format) posts#destroy
root GET / posts#index
以下是我的开发环境路线：
Prefix Verb URI Pattern Controller#Action
new_user_session GET /users/sign_in(.:format) devise/sessions#new
user_session POST /users/sign_in(.:format) devise/sessions#create
destroy_user_session GET /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
PATCH /users/password(.:format) devise/passwords#update
PUT /users/password(.:format) devise/passwords#update
cancel_user_registration GET /users/cancel(.:format) registrations#cancel
user_registration POST /users(.:format) registrations#create
new_user_registration GET /users/sign_up(.:format) registrations#new
edit_user_registration GET /users/edit(.:format) registrations#edit
PATCH /users(.:format) registrations#update
PUT /users(.:format) registrations#update
DELETE /users(.:format) registrations#destroy
post_comments GET /posts/:post_id/comments(.:format) comments#index
POST /posts/:post_id/comments(.:format) comments#create
new_post_comment GET /posts/:post_id/comments/new(.:format) comments#new
edit_post_comment GET /posts/:post_id/comments/:id/edit(.:format) comments#edit
post_comment GET /posts/:post_id/comments/:id(.:format) comments#show
PATCH /posts/:post_id/comments/:id(.:format) comments#update
PUT /posts/:post_id/comments/:id(.:format) comments#update
DELETE /posts/:post_id/comments/:id(.:format) comments#destroy
posts GET /posts(.:format) posts#index
POST /posts(.:format) posts#create
new_post GET /posts/new(.:format) posts#new
edit_post GET /posts/:id/edit(.:format) posts#edit
post GET /posts/:id(.:format) posts#show
PATCH /posts/:id(.:format) posts#update
PUT /posts/:id(.:format) posts#update
DELETE /posts/:id(.:format) posts#destroy
root GET / posts#index