title: Not all keys work when converting JSON String to NSDictionary
body: <p>I'm using the following code to convert a JSON string literal to an array holding an NSDictionary for each item:</p>
  
  <pre><code>NSString* json = @"[{\"name\":\"Item 1\",\"id\":\"999\",\"lang\":\"en\",\"type\":\"A\",\"version\":15}]";
  NSData* data = [json dataUsingEncoding:NSUTF8StringEncoding];
  NSArray* values = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
  </code></pre>
  
  <p>After removing the app from my test device, the app started crashing when attempting to access, in a <code>for</code> loop <code>values[i][@"name"]</code>. When viewing <code>values</code> in the inspector, I see the following:</p>
  
  <pre><code>values = (NSArray *) @"1 object"
      [0] = (__NSDictionaryM *) 5 key/value pairs
          [0] = (no summary) : @"Item 1"
          [1] = @"id" : @"999"
          [2] = @"type" : @"A"
          [3] = (no summary) : (long)15
          [4] = @"lang" : (no summary)
  </code></pre>
  
  <p>When expanded further, the keys that should be <code>name</code> and <code>version</code> are both shown to be the type <code>(__NSCFConstantString *)</code></p>
  
  <p>This was working prior to removing the app from the device, and no changes have been made to this section of the code.</p>
  
  <p>Any ideas on what could be causing this, or better ways to convert the json string to a dictionary?</p>
  
  <p><strong>UPDATE</strong>: I changed "name" and "version" to "game" and "gersion", and it worked perfectly.</p>