title: Rails 4.2: Internal Server Error with Maximum file multiparts in content reached
body: <p>Just upgraded to Rails 4.2 and I get Internal Server Error on localhost and in production when trying to edit a model with multiple has_many objects. This is the message I see on the rails s console</p>
  
  <pre><code>!! Unexpected error while processing request: Too many open files - Maximum file multiparts in content reached
  </code></pre>
  
  <p>The request does not even get to the controller i.e., I DO NOT see the usual following lines in rails s console</p>
  
  <pre><code>Started GET "/feeds/3/edit" for 127.0.0.1 at 2015-01-04 20:07:19 -0800
  Processing by FeedsController#edit as HTML
  ......
  ......
  </code></pre>
  
  <p>Any clues?? Using Ruby 2.1.5 upgraded to 2.2 with no luck.</p>