Unreal Engine Issues

Undo and ConstructionScript break the AttachChildren array

Undo fills AttachChildren array with null by the undo serializer. After that, a construction script tries to remove child components from parent component's AttachChildren but it can't find its poi ...

Infinite loop in UAnimSequence::ExtractRootMotion when sampling backwards

When sampling root motion backwards we can hit an infinite loop in ExtractRootMotion. This happens if the initial sample time + negative delta is off the end of the animation clip. In that case FA ...

Atmosphere Sunlight shafts, artifacts, for both cascaded and virtual shadow maps.

Very large objects casting dynamic shadows on the sky atmosphere can lead to flickering (cascaded shadow maps) or square patterns (virtual shadow maps). ...

Params in material instance disappear when grouping is changed in material with a material layer

If there is a texture parameter within a specific material attribute stream in the base material and also within the base material layer, they must have the same parameter group otherwise the parame ...

In UE 5.5, "Open Level By Name" is not able to find the map if the map is not added to "List of maps to include in a packaged build"

The "Open Level By Name" is not able to find the map to travel when the map is not included in the "List of maps to include in a packaged build" option. This issue was not happening in UE 5.3 and UE ...

Significant editor slowdowns when moving blueprinted actors while having a different complex blueprint open

A Blueprinted actor's construction script time can be affected by the complexity of an opened level Blueprint. ...

NavMesh debug material color is changed by lighting with high lux values.

There is a clear difference in color saturation for the nav mesh debug material between when lit by a light with low lux values (6) and when lit with high lux values (1000) and eye adaption is enabl ...

Broken TextureTest BP in Landmass plugin base content

It appears that the Landmass plugin has a content dependency on the BlueprintMaterialTextureNodes plugin. If the BlueprintMaterialTextureNodes is not loaded, then the blueprint "/Landmass/Landscape ...

Sampling textures with bias in the path of a custom data pin causes derivative operations when avoidable

Materials that make use of the analytical derivatives path to avoid hardware derivatives can still generate derivative operations on texture samples when the shading model has a custom data pin and ...

Deleting MPC referenced in material layer cause editor crash.