Unreal Engine Issues

ISM + WPO = broken motion vectors?

Instanced Static Meshes will have incorrect velocity if a Material uses World Position Offset. Fixed WPO in a material causes significant velocity on the ISM. This was also replicated in //UE5/Rele ...

[CrashReport] UE4Editor_Slate!TAttribute<FText>::Get() [attribute.h:130]

This is a common crash affecting users in 4.16 User DescriptionsI imported an FBX and the editor crashed.alembic import from brekelwhats wrong with the ue4 alembic importer? Source Context 120 ...

Crash when exposing a TOptional<FName> or TOptional<FText> to the editor through a UProperty.

Support 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 ...

[CrashReport] UE4Editor_SlateCore!FHittestGrid::GetBubblePath() [hittestgrid.cpp:145]

This 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

The 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 ...

Crash after generating HLODs for merged meshes that have all triangles culled

Crash after adding an AI Perception component to a parent and child character

Crash 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 ...

[CrashReport] Ensure condition failed: ToPin->LinkedTo.Contains(this)

This is a frequent and longstanding Ensure that has occurred for more than 500 users since at least the 4.13 release. Additionally, there do seem to be a few crashes with this callstack mixed among ...

Reference to control rig can be lost on actors with multiple skeletal mesh components

In the attached project, when we initially add a control rig track for the actor with multiple skeletal mesh components, we add the control rig for the correct component because FControlRigParameter ...

Light Function and World Position in 5.4

When rendering a Light Function into the Translucency Lighting Volume, the World Position Material Expression returns the position relative to the Camera (unrotated), not the World. This can be mor ...