This is due the this function:
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(preferredContentSizeChanged:) name:UIContentSizeCategoryDidChangeNotification object:nil];
ios6 doesn’t support “Dynamic Text Size” and I didn’t check if this function exists on the running iOS.
This now fixed and a bug fix version will be sent to Apple in a few minutes ago.
Sorry for the inconvenience.