Unreal Engine Issues

GAS: DefaultSubobject AttributeSet becomes invalid on duplicated blueprint

When a native actor 'AMyActorClass' creates AttributeSets as a default subobject via CreateDefaultSubobject, duplicating an actor blueprint based on AMyActorClass will result in a blueprint with an ...

Map placed actor binding to another actor's Event Dispatcher (multicast delegate) results in duplicate bindings after blueprint recompile

Context Blueprint actors placed on the map can bind to another actor's event. If an ActorB has a reference to ActorA, it can bind to an event dispatcher in A by creating an event node in ActorB's e ...

Change of rotation axis when switching solver

This alteration was introduced in the 'Found CL' field - and is likely an unintentional side effect of adding SIMD to the solver. There is a repro project attached, open up 'TestMap' and run to see ...

Sampling regions don't get created when creating a mesh.

I'm trying to use VFX in specific regions on a character and would normally use sampling regions to do it easily, however the mutable mesh that is generated doesn't seem to be creating any of the on ...

Dataprep crash

This question was created in reference to: [Link Removed] Last post fixed the import crash, but it seems it added another. If we hit Execute button twice in a row by mistake we get a crash with th ...

Navigation mesh is generated ignoring collision for ISM added by construction script

When opening a map with ISM in place, NavOctree is not updated because the ISM bounds are assumed invalid and the geometry is not taken into account in the navmesh build.  The following log output i ...

Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key causes a memory leak

When Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key, the function construct the default structure in-place on the given pointer without destroying the object. This behavior ca ...

FName no longer equals FName_None when constructed with a trailing underscore and digits in range of 1-9

When an FName is created with a trailing underscore and any number of digits in the range of 1-9 the trailing digits are used as the internal number value for the FName lookup. This results in the F ...

Landscape raytracing geometry always updates every frame

LOD 0 Landscape meshes are always updated in FLandscapeComponentSceneProxy::GetDynamicRayTracingInstances because* r.RayTracing.Geometry.Landscape.LODsUpdateEveryFrame* (GLandscapeRayTracingGeometry ...

Modifiers do not behave as expected when adding conflicting mappings of different priorities