Rendering partials with Rails 4 on heroku - heroku

Question

I'm trying to render partials in my view and it's breaking heroku, showing "We're sorry, but something went wrong".
It's been driving me mad. I think it's something to do with the asset pipeline, hopefully someone will know what I've done wrong.
Logs
2013-06-23T21:46:58.711440+00:00 app[web.1]:
> ActionView::Template::Error (Missing partial static_pages/gbgsynopsis,
> application/gbgsynopsis with {:locale=>[:en], :formats=>[:html],
> :handlers=>[:erb, :builder, :raw, :ruby, :jbuilder, :coffee]}.
> Searched in: 2013-06-23T21:46:58.711440+00:00 app[web.1]: *
> "/app/app/views" 2013-06-23T21:46:58.711440+00:00 app[web.1]: 19:
> <%= image_tag('GBG.jpg', class: "bookcover") %>
> 2013-06-23T21:46:58.711440+00:00 app[web.1]: 20:
> </div> 2013-06-23T21:46:58.711611+00:00 app[web.1]: 22:
> <%= render "gbgsynopsis" %> 2013-06-23T21:46:58.711611+00:00
> app[web.1]: app/views/static_pages/home.html.erb:22:in
> `_app_views_static_pages_home_html_erb__1233625768328599458_70301407659120' 2013-06-23T21:46:59.003669+00:00 heroku[router]: at=info method=GET
> path=/favicon.ico host=readerly.herokuapp.com fwd="86.156.197.140"
> dyno=web.1 connect=1ms service=4ms status=200 bytes=0
Gemfile
source 'https://rubygems.org'
ruby '2.0.0'
# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.0.0.rc2'
gem 'bootstrap-sass'
group :development do
gem 'sqlite3'
end
group :production do
gem 'pg'
gem 'rails_12factor'
end
View
<div class="row-fluid">
<div class="span4">
<%= image_tag('GBG.jpg', class: "bookcover") %>
</div>
<div class="span8">
<%= render "gbgsynopsis" %>
</div>
</div>

Answer 1

The following message is clear:
> ActionView::Template::Error (Missing partial static_pages/gbgsynopsis,
> application/gbgsynopsis with {:locale=>[:en], :formats=>[:html],
> :handlers=>[:erb, :builder, :raw, :ruby, :jbuilder, :coffee]}.
Rails can't find your partial. I guess it is in the wrong directory or has the wrong filename (e.g. missing the _ as a first character).
Have a look at http://xyzpub.com/en/ruby-on-rails/3.2/dynamische_webseiten.html#partials for some docu about partials.