Last Exception Backtrace:
0   CoreFoundation                	0x196d85e48 __exceptionPreprocess + 164 (NSException.m:202)
1   libobjc.A.dylib               	0x19005b8d8 objc_exception_throw + 60 (objc-exception.mm:356)
2   UIKitCore                     	0x199277cbc -[UIViewController _presentViewController:withAnimationController:completion:] + 4080 (UIViewController.m:0)
3   UIKitCore                     	0x199276c10 __63-[UIViewController _presentViewController:animated:completion:]_block_invoke + 92 (UIViewController.m:8982)
4   UIKitCore                     	0x19929a598 -[_UIViewControllerTransitionCoordinator _applyBlocks:releaseBlocks:] + 240 (UIViewControllerTransitioning.m:1148)
5   UIKitCore                     	0x199208a48 -[_UIViewControllerTransitionContext _runAlongsideCompletions] + 140 (UIViewControllerTransitioning.m:380)
6   UIKitCore                     	0x199207ad8 -[_UIViewControllerTransitionContext completeTransition:] + 128 (UIViewControllerTransitioning.m:292)
7   Wikipedia                     	0x1030409b0 closure #2 in TableOfContentsAnimator.animateTransition(_:duration:animations:completion:) + 8 (TableOfContentsAnimator.swift:189)
8   Wikipedia                     	0x1030409b0 partial apply for closure #2 in TableOfContentsAnimator.animateTransition(_:duration:animations:completion:) + 32 (<compiler-generated>:0)
9   Wikipedia                     	0x10304e1a4 thunk for @escaping @callee_guaranteed (@unowned Bool) -> () + 40 (<compiler-generated>:0)

Last Exception Backtrace:
0   CoreFoundation                	0x1bdef9f94 __exceptionPreprocess + 164 (NSException.m:202)
1   libobjc.A.dylib               	0x1b704c3d0 objc_exception_throw + 60 (objc-exception.mm:356)
2   UIKitCore                     	0x1c0286d98 -[UIViewController _presentViewController:withAnimationController:completion:] + 4052 (UIViewController.m:0)
3   UIKitCore                     	0x1c02fcd94 __63-[UIViewController _presentViewController:animated:completion:]_block_invoke_2 + 56 (UIViewController.m:8992)
4   UIKitCore                     	0x1bff966e0 +[UIView(Animation) performWithoutAnimation:] + 76 (UIView.m:14792)
5   UIKitCore                     	0x1c0285d7c __63-[UIViewController _presentViewController:animated:completion:]_block_invoke + 208 (UIViewController.m:8990)
6   UIKitCore                     	0x1c0264158 -[UIViewController _performCoordinatedPresentOrDismiss:animated:] + 396 (UIViewController.m:9254)
7   UIKitCore                     	0x1c0034f7c -[UIViewController _presentViewController:animated:completion:] + 188 (UIViewController.m:9002)
8   UIKitCore                     	0x1c0034db8 -[UIViewController presentViewController:animated:completion:] + 164 (UIViewController.m:9198)
9   Wikipedia                     	0x104783510 closure #1 in ArticleTableOfContentsDisplayController.showModal(animated:) + 76 (ArticleTableOfContentsDisplayController.swift:94)
10  Wikipedia                     	0x104783510 partial apply for closure #1 in ArticleTableOfContentsDisplayController.showModal(animated:) + 108 (<compiler-generated>:0)
11  Wikipedia                     	0x104631438 closure #1 in ArticleViewController.getVisibleSection(with:) + 408 (ArticleViewController+TableOfContents.swift:15)
12  Wikipedia                     	0x1045bcd78 thunk for @escaping @callee_guaranteed (@in_guaranteed Any?, @guaranteed Error?) -> () + 120 (<compiler-generated>:0)