Unreal Engine Issues

UE5.4 Regression - crash when disabling shader optimization while raytracing is enabled on D3D12

Certain interactions between a Rect Light with a Light Function and a Post-Process volume lead to a check() when compiling a Ray Tracing PSO for tracing lights. This check() only happens when shader ...

Niagara compiler error, branch in custom hlsl doesn't work properly

Sandbox Visitors can fail on empty directories on non-Windows platforms

When a Sandbox Visitor checks a directory and it doesn't exist, it returns true on Windows and false on other platforms. The code that uses the result of this check, IterateDirectory, doesn't conti ...

'Max World Position Offset Displacement' causes culling issue on HISMC/foliage in 5.4

Foliage/hierarchical instanced static mesh components have issues with culling when their material's "Max World Position Offset Displacement" value is a higher amount, e.g. 100.0. ...

Incorrect behavior after attaching an actor to a non-root component of another actor in the Editor

UE allows actors to be attached to other actors. More precisely, it allows the root component of an actor (child) to be attached to any component of another actor (parent). From now on, "parent" and ...

GPU Lightmass does not support bounce lighting from landscapes

GPU Lightmass does not support bounce lighting from landscapes, but CPU Lightmass does. ...

All public inline methods of class "FBlueprintEditor" are inaccessible to other modules due to "DLLIMPORT"

Class "FBlueprintEditor" has several inline getter methods as part of its public API (e.g. GetPreviewActor() and GetPreviewScene()). However, even though they are public, those methods are inaccessi ...

The light in the Blueprint Editor's Preview Scene does not respond to any lighting channel but 0.

In the Blueprint Editor, Primitive Components can be configured to respond to Lighting Channels 0, 1, and/or 2. However, if channel 0 is disabled (even with another one enabled), the Preview Actor's ...

Moving a mesh with complex-as-simple collision clears overlaps previously detected by moving collision components

Consider a static mesh set to use complex-as-simple collision, and a convex collision component, starting to overlap each other. When only the Collision Component moves, its collision with the stat ...

Incorrect error icon on stationary lights in a sublevel when the sublevel is first added

When you add a level with stationary lights to another level as a sublevel they will show a first error icon on the lights. Once you close the project or refresh the level this icon is shown as nor ...