Unreal Engine Issues

LevelEditor: "Replace Actor" marks level as dirty even when using external actors

When using external actors, adding/removing/replacing/editing an actor instance inside a level does not cause any modification to the Level package, which helps reduce contention for the map file on ...

[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 ...

[CrashReport] Undo crash - FD3D11DynamicRHI::RHIDrawIndexedPrimitive() [d3d11commands.cpp:1650]

This is a trending crash coming out of 4.18, although it also occurred with less frequency in 4.16 and 4.17. The callstack shares similarities to [Link Removed] and [Link Removed], and the user com ...

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_CoreUObject!FWeakObjectPtr::Get() [weakobjectptr.cpp:81]

This is a trending crash coming out of the 4.18 release. It may be a regression. User Descriptionscreated a physics asset and tried to open it... Source Context 66 if (!SerialNumbersMatc ...

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 ...

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 ...