All images in help section returns either "404 Not Found" or "500 Internal Server Error" response

Created by: alhashash

When opening the help section, no images are displayed (For example, in backup and workflow/groups sections).

I tried recompiling assets and restarting gitlab/nginx but got the same errors. The .png image files are available at the same location as the .md files and git status shows no change.

For example, .../help/workflow/groups/transfer_project.png returns 404 response. production.log shows:

Started GET "/help/workflow/groups/transfer_project.png" for 192.168.1.19 at 2014-08-26 20:03:56 +0300
Processing by NamespacesController#show as HTML
  Parameters: {"id"=>"help/workflow/groups/transfer_project.png"}
Completed 404 Not Found in 12ms (Views: 4.4ms | ActiveRecord: 2.3ms)

.../help/raketasks/backup_hrz.png returns 500 response. production.log shows:

Started GET "/help/raketasks/backup_hrz.png" for 192.168.1.19 at 2014-08-26 19:57:15 +0300
Processing by HelpController#show as PNG
  Parameters: {"category"=>"raketasks", "file"=>"backup_hrz"}
Completed 500 Internal Server Error in 6ms

ActionView::MissingTemplate (Missing template errors/not_found with {:locale=>[:en], :formats=>[:png], :variants=>[], :handlers=>[:erb, :builder, :raw, :ruby, :slim, :coffee, :haml]}. Searched in:
  * "/home/git/gitlab/app/views"
  * "/home/git/gitlab/vendor/bundle/ruby/gems/semantic-ui-sass-0.16.1.0/app/views"
  * "/home/git/gitlab/vendor/bundle/ruby/gems/kaminari-0.15.1/app/views"
  * "/home/git/gitlab/vendor/bundle/ruby/gems/devise-3.2.4/app/views"
  * "/home/git/gitlab"
  * "/"
):
  app/controllers/application_controller.rb:140:in `not_found!'
  app/controllers/help_controller.rb:12:in `show'

Here is the setup information:

System information
System:
Current User:   git
Using RVM:      no
Ruby Version:   2.0.0p353
Gem Version:    2.0.14
Bundler Version:1.7.2
Rake Version:   10.3.2
Sidekiq Version:2.17.0

GitLab information
Version:        7.2.0
Revision:       935ed64
Directory:      /home/git/gitlab
DB Adapter:     postgresql
URL:            https://xxx.xxxxxx.com
HTTP Clone URL: https://xxx.xxxxxx.com/some-project.git
SSH Clone URL:  git@xxx.xxxxxx.com:some-project.git
Using LDAP:     no
Using Omniauth: no

GitLab Shell
Version:        1.9.7
Repositories:   /home/git/repositories/
Hooks:          /home/git/gitlab-shell/hooks/
Git:            /usr/bin/git