After several minutes running all animations in my application disappeared, even system animations like alert animation and UINavigationController animations. What can be the issue?
P.S. I dont use [UIView setAnimationsEnabled] anywhere.
Well, the answer is - system sometimes disables animations, and, normally, it enables them back on. But in my case, for some reason, it failed to set them back enabled. And this happens only during transitions between UIViewControllers. What I came up with, is to reset [UIView setAnimationsEnabled:YES] after every transition.
来源：https://stackoverflow.com/questions/18920553/animations-disappear-in-ios-application-after-some-time