Hello there, we have an iOS application which has been out for quite some time with a custom WKWebView which has been throwing the following exception on the latest iOS 17.4 (Beta) The application appears to freeze / crash when interacting with input on a WKWebView. Our application also uses react-native, but up until this particular iOS version everything has been working smoothly (since about iOS 12.0 or so). Here is some more details on the environment iPhone 15 Pro (can reproduce on simulator as well) iOS 17.4 (Beta) Physical device * thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BREAKPOINT (code=1, subcode=0x1a195a918) * frame #0: 0x00000001a195a918 WebKit`WTFCrashWithInfo(int, char const*, char const*, int) + 20 frame #1: 0x00000001a25ef8fc WebKit`-[WKContentView(WKInteraction) textInputTraits] + 288 frame #2: 0x00000001c77689c8 PencilKit`+[PKTextInputUtilities textInputTraitsFromTextInput:] + 112 frame #3: 0x00000001c7768be8 PencilKit`+[PKTextInputUtilities isResponderSupportedTextInput:checkForNotes:outTextInputTraits:] + 64 frame #4: 0x00000001c77d5128 PencilKit`+[PKTextInputElementsFinder isResponderEditableTextInput:] + 56 frame #5: 0x00000001c78f29a0 PencilKit`-[PKTextInputWindowFirstResponderController _updateFirstResponder:isVisible:sendDelegateCallback:] + 224 frame #6: 0x00000001c78f2dd8 PencilKit`-[PKTextInputWindowFirstResponderController _textInputResponderDidChangeNotificationHandler:] + 244 frame #7: 0x000000018c7b67a8 CoreFoundation`__CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 148 frame #8: 0x000000018c7b6170 CoreFoundation`___CFXRegistrationPost_block_invoke + 88 frame #9: 0x000000018c7b60b8 CoreFoundation`_CFXRegistrationPost + 440 frame #10: 0x000000018c7b5608 CoreFoundation`_CFXNotificationPost + 728 frame #11: 0x000000018b65ee10 Foundation`-[NSNotificationCenter postNotificationName:object:userInfo:] + 92 frame #12: 0x000000018f63b02c UIKitCore`-[UIKeyboardImpl _postInputResponderChangedNotification] + 224 frame #13: 0x000000018f63c74c UIKitCore`-[UIKeyboardImpl _setDelegate:existingDelegate:force:delayEndInputSession:] + 480 frame #14: 0x000000018ebd4368 UIKitCore`-[UIKeyboardImpl setDelegate:force:delayEndInputSession:] + 664 frame #15: 0x000000018eb931a8 UIKitCore`-[UIKeyboardSceneDelegate _reloadInputViewsForKeyWindowSceneResponder:force:fromBecomeFirstResponder:] + 2916 frame #16: 0x000000018eb92604 UIKitCore`-[UIKeyboardSceneDelegate _reloadInputViewsForResponder:force:fromBecomeFirstResponder:] + 88 frame #17: 0x000000018f860ee4 UIKitCore`-[UIResponder(UIResponderInputViewAdditions) reloadInputViews] + 84 frame #18: 0x00000001a25f3cb4 WebKit`-[WKContentView(WKInteraction) _elementDidFocus:userIsInteracting:blurPreviousNode:activityStateChanges:userObject:] + 1800 frame #19: 0x00000001a1f58024 WebKit`WebKit::PageClientImpl::elementDidFocus(WebKit::FocusedElementInformation const&, bool, bool, ***::OptionSet<WebCore::ActivityState>, API::Object*) + 108 frame #20: 0x00000001a1f8713c WebKit`WebKit::WebPageProxy::elementDidFocus(WebKit::FocusedElementInformation const&, bool, bool, ***::OptionSet<WebCore::ActivityState>, WebKit::UserData const&) + 168 frame #21: 0x00000001a252b9d0 WebKit`WebKit::WebPageProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 24380 frame #22: 0x00000001a263f628 WebKit`IPC::MessageReceiverMap::dispatchMessage(IPC::Connection&, IPC::Decoder&) + 264 frame #23: 0x00000001a20e9be0 WebKit`WebKit::WebProcessProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 44 frame #24: 0x00000001a263a690 WebKit`IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder>>) + 324 frame #25: 0x00000001a263abb0 WebKit`IPC::Connection::dispatchIncomingMessages() + 708 frame #26: 0x00000001a2887524 JavaScriptCore`***::RunLoop::performWork() + 204 frame #27: 0x00000001a288844c JavaScriptCore`***::RunLoop::performWork(void*) + 36 frame #28: 0x000000018c7be62c CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28 frame #29: 0x000000018c7bd8a8 CoreFoundation`__CFRunLoopDoSource0 + 176 frame #30: 0x000000018c7bc0b8 CoreFoundation`__CFRunLoopDoSources0 + 340 frame #31: 0x000000018c7bad88 CoreFoundation`__CFRunLoopRun + 828 frame #32: 0x000000018c7ba968 CoreFoundation`CFRunLoopRunSpecific + 608 frame #33: 0x00000001d0ecf4e0 GraphicsServices`GSEventRunModal + 164 frame #34: 0x000000018ec37350 UIKitCore`-[UIApplication _run] + 888 frame #35: 0x000000018ec3698c UIKitCore`UIApplicationMain + 340 frame #36: 0x0000000100499dec Padlet`main(argc=1, argv=0x000000016f96f708) at main.m:8:14 frame #37: 0x00000001b00fed84 dyld`start + 2240 Stack traces generated with bt command. The crash mentions PencilKit but afaik we aren't supporting that here. Any help would be greatly appreciated, many thanks!