Sporadic crash on iOS

Question

Hi all,

I see sporadic crashs of my Xamarin app on iOS with the following stacktrace:

Last Exception Backtrace:
0   CoreFoundation                  0x19cbf2754 __exceptionPreprocess + 220 (NSException.m:199)
1   libobjc.A.dylib                 0x1b16b97a8 objc_exception_throw + 60 (objc-exception.mm:565)
2   CoreAutoLayout                  0x1b19447d0 _AssertAutoLayoutOnAllowedThreadsOnly + 416 (NSISEngine.m:0)
3   CoreAutoLayout                  0x1b19444a4 -[NSISEngine _optimizeWithoutRebuilding] + 72 (NSISEngine.m:1638)
4   CoreAutoLayout                  0x1b1943f7c -[NSISEngine optimize] + 108 (NSISEngine.m:1612)
5   CoreAutoLayout                  0x1b193f584 -[NSISEngine performPendingChangeNotifications] + 116 (NSISEngine.m:630)
6   UIKitCore                       0x19fb0d92c -[UIView(Hierarchy) layoutBelowIfNeeded] + 244 (UIView.m:12199)
7   UIKitCore                       0x19ede4b84 -[UINavigationController _positionNavigationBarHidden:edge:initialOffset:] + 764 (UINavigationController.m:2484)
8   UIKitCore                       0x19ede4dcc -[UINavigationController _positionNavigationBarHidden:edge:] + 396 (UINavigationController.m:0)
9   UIKitCore                       0x19edf8dd0 -[UINavigationController __viewWillLayoutSubviews] + 260 (UINavigationController.m:7241)
10  UIKitCore                       0x19edda944 -[UILayoutContainerView layoutSubviews] + 228 (UILayoutContainerView.m:89)
11  UIKitCore                       0x19fb21a0c -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 2576 (UIView.m:17543)
12  QuartzCore                      0x19ffa8670 -[CALayer layoutSublayers] + 308 (CALayer.mm:10147)
13  QuartzCore                      0x19ffa8b54 CA::Layer::layout_if_needed(CA::Transaction*) + 548 (CALayer.mm:10014)
14  QuartzCore                      0x19ffbd78c CA::Layer::layout_and_display_if_needed(CA::Transaction*) + 144 (CALayer.mm:2485)
15  QuartzCore                      0x19feff5e4 CA::Context::commit_transaction(CA::Transaction*, double, double*) + 500 (CAContextInternal.mm:2510)
16  QuartzCore                      0x19ff2b7f4 CA::Transaction::commit() + 684 (CATransactionInternal.mm:449)
17  QuartzCore                      0x19ff2c020 CA::Transaction::release_thread(void*) + 232 (CATransactionInternal.mm:641)
18  libsystem_pthread.dylib         0x1e875ce4c 0x1e8753000 + 40524
19  libsystem_pthread.dylib         0x1e8754c5c 0x1e8753000 + 7260
20  libsystem_pthread.dylib         0x1e8754100 0x1e8753000 + 4352
21  Ebba.iOS                        0x106e66084 0x104c88000 + 35512452
22  Ebba.iOS                        0x106e064e4 0x104c88000 + 35120356
23  libsystem_pthread.dylib         0x1e8754bfc 0x1e8753000 + 7164
24  libsystem_pthread.dylib         0x1e875d758 0x1e8753000 + 42840

Any hints as to where to search for the problem?

Thank you in advance and best regards
Markus