Unreal Engine Issues
Unreal Engine Issues
iOS/tvOS fails to build from source editor built with Xcode 9.3, macro expansion producing 'defined' has undefined behavior
UE - Platform - Mobile - Apr 2, 2018Trying to launch on or package for TVOS or iOS from a source build of Mac or Windows will fail with errors:[2018.04.02-16.35.08:522][634]LogPlayLevel: In file included from /Volumes/Storage/GitHub ...
[CrashReport] UE4Editor-Core.dylib!FTextHistory::Rebuild(TSharedRef<FString,()
UE - Platform - Apple - Aug 15, 2017This is a trending Mac crash in 4.17.0 that has also occurred with some frequency since at least 4.14. I have not been able to identify any matching callstack occurring on Windows, although it does ...
VerboseCookerWarning warnings: Saving object into cooked package %s which was created at cook time, Object Name UniqueObjectNameForCooking_0, Full Path %s, Outer class %s
UE - Foundation - Data Pipeline - Cooker - Jun 19, 2023Creating objects at cook time that are exported into the cooked package is a possible cause of indeterminism, and therefore we have banned it in engine classes and will fire a warning about it. Cur ...
[CrashReport] UE4Editor-ApplicationCore.dylib!FMacWindow::ApplySizeAndModeChanges()
UE - Platform - Apple - Oct 27, 2017This is an early trending Mac crash in 4.18. Users have not provided any descriptions of their actions when the crash occurred. Callstack from LogLogAssetRegistry: Asset discovery search completed ...
[CrashReport] Mac Metal crash - FSceneRenderer::RenderDistortion()
UE - Graphics Features - Aug 29, 2017This is a somewhat common Mac crash occurring since 4.15 and into 4.17.1. Users have not provided any descriptions of their actions when the crash occurred. This specific callstack was previously ...
GAS: Async loaded GameplayCueNotify can execute cue events out of order
UE - Gameplay - Gameplay Ability System - Mar 22, 2025Licensee reported problem via UDN. Context GameplayCues ('cue') are events that can be fired by game code, that are identified via a GameplayTag. Cues can be instantaneous or can be a state on any ...
[CrashReport] Mac crash - UE4Editor-AudioEditor.dylib!FSoundCueEditor::DeleteInput()
UE - Platform - Apple - Sep 14, 2017This is an infrequent Mac crash that has occurred for users since 4.16. Users have not provided any descriptions of their actions when the crash occurred. There is no record of a similar callstack ...
Ensure condition failed: bPlayingBackwards ? (CurrentPosition <= PreviousPosition) : (CurrentPosition >= PreviousPosition)
UE - Anim - Sequencer - May 10, 2022The problem is caused by the animation sequence playback position being set out of range from Sequencer. The call stack is : UE4Editor-AnimGraphRuntime.dll!FAnimSequencerInstanceProxy::UpdateAnim ...
Xcode 26/16.4 Metal Toolchain generates metallib's that are not compatible with iOS 16
UE - Platform - Apple - Sep 23, 2025Below is the error output from FirstPerson template as a C++ project: {+}../../../FirstPerson58CPP/Content/firstperson58cpp_sf_metal_es3_1_ios-metal_es3_1_ios.0.metallib, 5881486 bytes!2025-09-23 1 ...
[CrashReport] Mac crash - FShaderCompilingManager::ProcessCompiledShaderMaps()
UE - Graphics Features - Nov 16, 2017This is an infrequent Mac crash in the 4.18 release. The callstack is a match to [Link Removed] (loading Zen editor on Mac), but that was confirmed fixed for 4.18.0 while this continues for users. ...