Unreal Engine Issues

Crash handling: Prevent reports of assertions during shutdown after an assertion

CriticalErrors in FWindowsErrorOutputDevice::Serialize (and other platforms) run some code after the error is detected rather than immediately terminating the process. Some of this other code is spe ...

Motion Matching: Check failure when adding sequence into DB that references a niagara emitter

The serialization code for the motion matching database has a check that will fail if a property has the IgnoreForMemberInitializationTestName meta tag.  Niagara emitters contain a property that has ...

Assertion failed on reimporting FBX scene

Following code works as a work around : void SFbxSceneStaticMeshReimportListView::OnChangedOverrideOptions(TSharedPtr<FString> ItemSelected, ESelectInfo::Type SelectInfo) { #if 0 check(ItemSele ...

Lightmap UV generated on Windows and Mac is not deterministic

USplineMeshComponent::CalcBounds may return invalid value

USplineMeshComponent::CalcBounds function should be returning an FBoxSphereBounds type, but in the implementation it instead outputs an FBox. This may result in the returning of invalid results, esp ...

LOD dithered fade-out transition does not work since UE5.4

When DitheredLODTransition is enabled for HierarchicalInstancedStaticMesh, in the previous version (5.1.1), dithering was applied during fade-in/fade-out, but in 5.4.3, dithering is not applied duri ...

Material base color is lighter on Nanite meshes when using 16-bit GBuffer

The base color is brighter on Nanite meshes than non-Nanite meshes when GBuffer Format is set to "Force 16-bits per channel" (r.GBufferFormat 5) even though the meshes are using the same material. ...

MemReport does not seem to respect mesh streaming

The function "FStaticMeshLODResources::GetResourceSizeEx(...)" does not take into account that the buffers might be emptied, due to Mesh Streaming. This causes "obj list" to report sizes larger than ...

Screen Probes and Specular Firefly Flickering near screen edges

Lumen's rough specular indirect lighting buffer can have fireflies along the bottom and right edges of the screen. Also tested in //UE5/Main, CL: 35177423 ...

Crash when a subsystem calls GetSubsystemArray() on its owner while engine code is iterating on subsystems also obtained through GetSubsystemArray()

In some occasions, engine code iterates over a certain subsystem type by calling FSubsystemCollection::GetSubsystemArray() and then calling some method on all subsystems of the returned array. This ...