title: Invalid parameter exception thrown by _UIQueuingScrollView
body: <p>My app that contains a UITableViewController embedded in UIPageViewController raises this exception from time to time:</p>
  
  <pre><code>Invalid parameter not satisfying: [views count] == 3
  </code></pre>
  
  <p>Backtrace:</p>
  
  <pre><code>* thread #1: tid = 0x6239fa, 0x03d1d88a libobjc.A.dylib`objc_exception_throw, queue = 'com.apple.main-thread, stop reason = breakpoint 25.3
      frame #0: 0x03d1d88a libobjc.A.dylib`objc_exception_throw
      frame #1: 0x0404f448 CoreFoundation`+[NSException raise:format:arguments:] + 136
      frame #2: 0x03428fee Foundation`-[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 116
      frame #3: 0x01e7c535 UIKit`-[_UIQueuingScrollView _replaceViews:updatingContents:adjustContentInsets:animated:] + 185
      frame #4: 0x01e800ca UIKit`-[_UIQueuingScrollView _didScrollWithAnimation:force:] + 1231
      frame #5: 0x01e7bb57 UIKit`-[_UIQueuingScrollView _scrollViewAnimationEnded:finished:] + 104
      frame #6: 0x0190583c UIKit`-[UIScrollView(UIScrollViewInternal) animator:stopAnimation:fraction:] + 62
      frame #7: 0x0197096e UIKit`-[UIAnimator stopAnimation:] + 533
      frame #8: 0x0197100a UIKit`-[UIAnimator(Static) _advanceAnimationsOfType:withTimestamp:] + 325
      frame #9: 0x01970b76 UIKit`-[UIAnimator(Static) _LCDHeartbeatCallback:] + 67
      frame #10: 0x01663b8a QuartzCore`CA::Display::DisplayLinkItem::dispatch() + 48
      frame #11: 0x01663a46 QuartzCore`CA::Display::DisplayLink::dispatch_items(unsigned long long, unsigned long long, unsigned long long) + 310
      frame #12: 0x01663f6b QuartzCore`CA::Display::TimerDisplayLink::callback(__CFRunLoopTimer*, void*) + 123
      frame #13: 0x0400dbd6 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 22
      frame #14: 0x0400d5bd CoreFoundation`__CFRunLoopDoTimer + 1181
      frame #15: 0x03ff5628 CoreFoundation`__CFRunLoopRun + 1816
      frame #16: 0x03ff4ac3 CoreFoundation`CFRunLoopRunSpecific + 467
      frame #17: 0x03ff48db CoreFoundation`CFRunLoopRunInMode + 123
      frame #18: 0x0533b9e2 GraphicsServices`GSEventRunModal + 192
      frame #19: 0x0533b809 GraphicsServices`GSEventRun + 104
      frame #20: 0x01874d3b UIKit`UIApplicationMain + 1225
  </code></pre>
  
  <p>Does anyone have seen this already or have an idea what the reason could be?</p>