This crash happens online and cannot be tested and reproduced. I need help. Thank you very much. Exception Type: EXC_BREAKPOINT (SIGTRAP) Exception Codes: 0x0000000000000001, 0x000000018b4190d0 Exception Note: EXC_CORPSE_NOTIFY Termination Reason: SIGNAL 5 Trace/BPT trap: 5 Terminating Process: exc handler [338] Triggered by Thread: 7 Last Exception Backtrace: 0 CoreFoundation 0x180cd7c60 __exceptionPreprocess + 216 (NSException.m:200) 1 libobjc.A.dylib 0x198507ee4 objc_exception_throw + 56 (objc-exception.mm:565) 2 CoreAutoLayout 0x1987cb000 _AssertAutoLayoutOnAllowedThreadsOnly + 412 (NSISEngine.m:0) 3 CoreAutoLayout 0x1987cdb7c -[NSISEngine withBehaviors:performModifications:] + 32 (NSISEngine.m:1975) 4 UIKitCore 0x1831262fc -[UIView _resetLayoutEngineHostConstraints] + 80 (NSLayoutConstraint_UIKitAdditions.m:1426) 5 UIKitCore 0x1830fc0c0 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 2376 (UIView.m:18416) 6 QuartzCore 0x18477c520 CA::Layer::layout_if_needed(CA::Transaction*) + 528 (CALayer.mm:10118) 7 QuartzCore 0x18476f294 CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 132 (CALayer.mm:2480) 8 QuartzCore 0x184782cc8 CA::Context::commit_transaction(CA::Transaction*, double, double*) + 464 (CAContextInternal.mm:2612) 9 QuartzCore 0x18478b79c CA::Transaction::commit() + 708 (CATransactionInternal.mm:449) 10 QuartzCore 0x1847dfe04 CA::Transaction::release_thread(void*) + 224 (CATransactionInternal.mm:651) 11 libsystem_pthread.dylib 0x1dc052d90 _pthread_tsd_cleanup + 520 (pthread_tsd.c:388) 12 libsystem_pthread.dylib 0x1dc055c08 _pthread_exit + 80 (pthread.c:1717) 13 libsystem_pthread.dylib 0x1dc05124c _pthread_wqthread_exit + 100 (pthread.c:2559) 14 libsystem_pthread.dylib 0x1dc050e88 _pthread_wqthread + 420 (pthread.c:2593) 15 libsystem_pthread.dylib 0x1dc05092c start_wqthread + 8 (:-1)