Heroku Rails deployment successful but Application Error
<p><strong>*Edited</strong></p>

<p>In trying to deploy my Rails 4 app onto Heroku, I kept getting error messages even though my deployment was successful. I also needed to translate my app from using sqlite3 to postgres (edits to database.yml) What helped me was running:</p>

<pre><code>heroku logs -- myAppName
</code></pre>

<p>where as before, I was only doing:</p>

<pre><code>heroku logs
</code></pre>

<p>An error I got was a MissingTemplate.
I found that I needed to update my production.rb file to include:</p>

<pre><code>config.assets.compile = true
</code></pre>

<p>and in my <strong>Gemfile</strong></p>

<pre><code>group :production, :staging do
    gem 'haml'
    gem 'rails_12factor'
end
</code></pre>