Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
2018-03-06 18:30:19.141870+0100 Myapp[1125:200711] *** Assertion failure in -[UIView _nsis_center:bounds:inEngine:forLayoutGuide:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKit/UIKit-3698.21.8/NSLayoutConstraint_UIKitAdditions.m:3322
2018-03-06 18:30:19.142162+0100 Myapp[1125:200711] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Error in compatibility flow'
*** First throw call stack:
(0x181f31d04 0x181180528 0x181f31bd8 0x1828c1c24 0x18be652a4 0x18c0bed04 0x18c0beee4 0x193a6f418 0x193a6ee20 0x18b3662f8 0x185f1fec8 0x185f23fa8 0x18b37b09c 0x18adf790c 0x18adf3c38 0x106db549c 0x106db545c 0x106dba050 0x181ed9eb0 0x181ed7a8c 0x181df7fb8 0x183c8ff84 0x18b3cc2e8 0x10483fca4 0x18191a56c)
libc++abi.dylib: terminating with uncaught exception of type NSException
I am getting this log when I try to load a youTube video with YouTube Helper library.
I implemented the YTPlayerView in a cell and got the previous error. Then I tried out to open it in a normal UIViewController. Same problem again.
The Video starts to play inline as aspected, but when I click on the fullscreen mode button I get SIGABRT in AppDelegate.
This problem came up since I work with xcode 9. With older versions it works like expected. When I compile same code on iOS 10 Device it is working. With iOS 11 not.
I found out that the AVPlayer in UIWebView wants to use contraints but I am using Autolayout... I tried to add a symbolic breakpoint using this post How to trap on UIViewAlertForUnsatisfiableConstraints?
Found the reason. I guess the SDK was broke. Reinstall XCODE did the trick!