title: iOS5 convert project to ARC fails due to "Error in format of file" How to fix?
body: <p>I got a project with <strong>49 source files</strong> that I'm trying to convert to ARC using <strong>edit>refactor>convert to arc</strong>. I click "pre-check", <strong>there are no errors</strong>, and the target compiles.</p>
  
  <p>Xcode goes through "generating preview", <strong>compiles all 49 source files</strong>, then shows me 1 (or 2) file in the review changes list. This is a .h/.m file. That one appears correct. There are no other files on that list and I see.</p>
  
  <p>When I click save, the window closes, and the project tries to build, but fails with error:</p>
  
  <pre><code>Error in format of file: ...-arc.migrate/remap
  </code></pre>
  
  <p>These errors appearing in all files</p>
  
  <p>If I try to build the project, i get ~350 errors saying "retain, release not allowed in ARC"... Please help!</p>
  
  <p>How do I convert the entire project to ARC at once?</p>
  
  <p><strong>Update: After cleaning the project a bunch of times and changing the deployment target to iPhone 5 simulator, I was able to see all files in the "save changes" list.</strong> </p>