title: Why would this app crash 100% when running from Testflight, maybe 10% from Xcode
body: <h2>EDIT: I am going to repost a different version of this - I think I was focusing too hard on the fact it crashes in Testflight and not on the fact it crashes on iPhone but not iPad. (even from TF)</h2>
  
  <p>I'm having an annoying problem, and previous similar answers on SO aren't helping much.</p>
  
  <p>I have a game (using Sprite Kit) which sometimes crash when a certain method finishes running. It does this 10% (or less) of the time when I run it on my iPhone 5s from Xcode, but if I upload to Testflight, it does it 100% of the time.</p>
  
  <p>Xcode doesn't give me great debugging info, it shows a green breakpoint line in main.m on this line:</p>
  
  <pre><code>return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
  </code></pre>
  
  <p>and on the left panel it says this happens in:</p>
  
  <p>Thread 1:</p>
  
  <blockquote>
    <p>Queue: com.apple.spritekit.renderQueue 0
    SKCRenderer::preprocessSpriteImp(std::__1::vector >&amp;,
    SKRenderQuadPool&amp;, SKCSprite const*, _GLKMatrix4 const&amp;, float,
    unsigned int&amp;, bool)const</p>
    
    <p>and I see an EXC_BAD_ACCESS (code=EXC_I386_GPFLT) in this line:</p>
    
    <p>0x1015bc663:  movq   16(%rbx), %rcx</p>
  </blockquote>
  
  <p><a href="http://i.stack.imgur.com/F73r6.png" rel="nofollow">I will attach a pic actually of the surrounding stuff</a></p>
  
  <p>I am bad at debugging and I don't know what to do. One notable thing is that this never happens in the iPad version. I'm very confused as to why it would happen sometimes but not always.</p>