Unreal Engine Issues
Unreal Engine Issues
Crash when exposing a TOptional<FName> or TOptional<FText> to the editor through a UProperty.
UE - Editor - Mar 25, 2025Support for editor-exposed uproperties of type TOptional<T> has been added by CL 28199740 on september 2023. However, since then until today in UE 5.5, a crash can happen when exposing TOptional<FNa ...
Adding new elements to an array in code does not update in a class based blueprint on compile
UE - Gameplay - Blueprint - May 5, 2015When adding elements to an array inside a code class, blueprint instances of the class do not have their array updated after a hot reload. ...
Collision outcome is different between PIE and Mobile Preview/Packaged Project.
UE - Simulation - Physics - Mar 25, 2015When playing the user's project in editor vs Packaged, there has been different results for the enemies collision. When playing in PIE, you are able to fly through the enemies with no issues. When p ...
Maya Generated FBX Files Fail to Import Properly into UE 4.10
Tools - Nov 24, 2015The same animation FBX file generated from Maya will import correctly into UE4.9 but incorrectly into UE4.10. Moreover, if you generate an FBX from the animation that was successfully imported from ...
Problem with material layers using interpolator nodes
UE - Rendering - Architecture - Materials - Jun 7, 2024The Vertex Interpolator Material Expression appears to collapse separate instances from separate Material Layers, leading to visual artifacts when used. Also tested on UE5_Main, CL: 34200103 ...
[CrashReport] UE4Editor_SlateCore!FHittestGrid::GetBubblePath() [hittestgrid.cpp:145]
UE - Editor - UI Systems - Slate - Oct 27, 2017This is a trending crash coming out of the 4.18 release. Users have not provided any descriptions of their actions when the crash occurred. Based on the affected project names, this crash seems co ...
Orientation Warping breaks incoming poses where bones are in component space
UE - MVF Character - Animation - Apr 17, 2025The orientation warping node breaks incoming poses where bones are already in component space. This is because, in EvaluateSkeletalControl_AnyThread, we are repeatedly setting bone transforms direc ...
Custom Primitive Data color widget not applying correctly to static mesh components in Blueprint editor.
UE - Rendering - Architecture - Materials - Jul 23, 2025Context Custom Primitive Data is used to store custom data in an index array that is accessible through Blueprint and code. This allows for variations across instances of the same mesh without needi ...
Changing bIsSpatiallyLoaded can cause an Actor to be duplicated during Play-In-Editor
UE - World Creation - Worldbuilding Tools - World Partition - Dec 18, 2025Changing bIsSpatiallyLoaded can cause an Actor to be duplicated during Play-In-Editor. As described in the steps to reproduce, if we keep swapping bIsSpatiallyLoaded state and save a Streaming Level ...
Crash after adding an AI Perception component to a parent and child character
UE - Gameplay - Sep 14, 2017Crash after adding an AI Perception component to a parent and child character. First they both must have had AI Perception components > Compiled and saved > Then both AI Perception components delete ...