Unreal Engine Issues
Unreal Engine Issues
Unable to launch project from Visual Studio using installed engine build
UE - Foundation - Build - Farm - Feb 23, 2017When a code project's engine association is switched to a local binary version of a source engine, the project will fail to open from within Visual Studio. Error message says that UE4Editor-Project ...
Phaser module is malfunctioning
UE - Audio - Apr 9, 2019The phaser module that is part of the new Audio Engine causes audio from a Sound Cue to mute after playing for one second. The user states that the issue comes from the Phaser.cpp file producing a N ...
Python crash the engine at exit.
UE - Editor - Workflow Systems - Oct 25, 2022A UDN reported various crashes at exit in the embedded Python library. I was able to repro the issue in Release-5.1 and trace it back at the point where python runs its garbage collection in Py_Fina ...
Crash in AWorldDataLayers::InitializeDataLayerRuntimeStates() when quickly unloading then loading a sub-world partition
UE - World Creation - Worldbuilding Tools - Data Layers - Mar 6, 2025From licensee: Since we integrated 5.5, we are experiencing a crash in AWorldDataLayers::InitializeDataLayerRuntimeStates() on this line check(ActiveDataLayerNames.IsEmpty() && LoadedDataLayerN ...
Custom Depth range is different than Pixel Depth range
UE - Graphics Features - Sep 25, 2025Shaders that compare custom depth and pixel depth get wrong output values because the ranges are different. This error is most noticeable over large distances. The difference in ranges is due to t ...
NVIDIA 5080 GPU Crash when launching City Sample with DX12
UE - Graphics Features - Lumen - Apr 16, 2025UPDATE This issue no longer reproduces on driver versions 580.88 and higher. City Sample game crashes immediately upon opening with a NVIDIA 5080 with the latest drivers as well as some previous dr ...
Landscape 'crack free displacement' option causes landscape layer coords and UVs to be wrong
UE - LD & Modeling - Terrain - Landscape - Aug 25, 2015If you check the 'crack free displacement' option in a landscape material, it seems to break the results of both the landscape layer coords and regular UV input node. Worldposition is not affected. ...
[CrashReport] UE4Editor_UMG!TBaseDelegate<FMargin>::operator=() [delegatesignatureimpl.inl:381]
UE - Editor - UI Systems - Aug 29, 2017This is a longstanding and common UMG crash that has affected more than 200 users since at least the 4.15 release. User DescriptionsI was working in the UI and undid several last changes in quick s ...
[CrashReport] UE4Editor_UnrealEd!FBlueprintCompileReinstancer::ReplaceInstancesOfClass_Inner() [kismetreinstanceutilities.cpp:1880]
UE - Gameplay - Blueprint Compiler - Oct 5, 2017This is a somewhat common crash that has occurred throughout the 4.17 release. Users have not provided any description of their actions when the crash occurred. The callstack is similar to some ol ...
PakFiles: Unmounting PakFile while requests are still in progress causes assertion failure in UnMount
UE - Foundation - Mar 31, 2022[Link Removed] Licensee is using the chunk downloader. On Shutdown method of their GameInstance, they call FChunkDownloader->Finalize. When they quit the game (Alt+F4) during a chunck download an a ...