Same problem, in our app using WKWebView, iOS 18 only #0 xxxxxx NSRangeException NSMutableRLEArray objectAtIndex:effectiveRange:: Out of bounds 0 CoreFoundation ___exceptionPreprocess + 164 1 libobjc.A.dylib _objc_exception_throw + 88 2 Foundation _blockForLocation 3 WebKit ___70-[WKContentView(WKInteraction) setAttributedMarkedText:selectedRange:]_block_invoke + 156 4 WebKit -[WKContentView(WKInteraction) setAttributedMarkedText:selectedRange:] + 136 5 UIKitCore -[UIResponder(UITextInput_Internal) _setAttributedMarkedText:selectedRange:] + 120 6 UIKitCore -[UIKBInputDelegateManager setAttributedMarkedText:selectedRange:] + 152 7 UIKitCore -[_UIKeyboardStateManager _setAttributedMarkedText:selectedRange:inputString:lastInputString:searchString:compareAttributes:] + 696 8 UIKitCore -[_UIKeyboardStateManager setMarkedText:selectedRange:inputString:lastInputString:searchString:candidateOffset:liveConversionSegments:highlighSegmentIndex:] + 692 9 UIKitCore -[_UIKeyboardStateManager assertIntermediateText:] + 200 10 UIKitCore -[_UIKeyboardStateManager syncKeyboardToConfiguration:] + 144 11 UIKitCore ___64-[_UIKeyboardStateManager handleKeyboardInput:executionContext:]_block_invoke_2 + 988 12 UIKitCore -[UIKeyboardTaskEntry execute:] + 208 13 UIKitCore -[UIKeyboardTaskQueue continueExecutionOnMainThread] + 324 14 Foundation ___NSThreadPerformPerform + 264 15 CoreFoundation _CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 28 16 CoreFoundation ___CFRunLoopDoSource0 + 176 17 CoreFoundation ___CFRunLoopDoSources0 + 244 18 CoreFoundation ___CFRunLoopRun + 840 19 CoreFoundation _CFRunLoopRunSpecific + 572 20 GraphicsServices _GSEventRunModal + 164 21 UIKitCore -[UIApplication _run] + 816 22 UIKitCore _UIApplicationMain + 340 23 XXXX main (main.m:18) 24 dyld 0x00000001aa99d000 + 212276