Unreal Engine Issues

If a mesh contains more than 32 material slots, it can cause a hash collision when computing the Raytracing CachedMeshCommandHash

FBlackboardKeySelector filters aren't applied when recompiling blueprint if a behavior tree asset containing the blueprint added as a service is closed, or if the blueprint is reparented.

Context In Behavior Trees, BT Services can be added to nodes. Those services can have configurable FBlackboardKeySelectors. BlackboardKeys are variables on a blackboard that the behavior tree can r ...

Cloth Asset - Crash when importing morph targets into clothing

The sim morph import has been broken after a change to make it work for cooked assets. Ticking the Import Sim Morph Targets checkbox crashes as soon as a skeletal mesh with morph target is specifie ...

Child actor components fail to attach in cooked builds when mobility is set to movable and end up at the origin

Context: A Child Actor Component allows an actor in Unreal Engine to contain another actor as its child (component). Problem: The problem is inconsistent handling of child actor component mobility ...

Snap to nearest spline point no longer working in 5.6. Right clicking on a spline point and using the option “Snap to nearest spline point" will no longer snap that point to any nearby spline and will sometimes cause the spline to snap to itself.

Context: When editing SplineComponents in the level viewport, right clicking a spline point has a context menu action "Snap to nearest spline point". Problem: The problem is, Snap to nearest spline ...

[PCG] Undoing the deletion of a pcg actor removes the Instance Category from the pcg component, specifically no graph parameter can be seen.

Context: PCGComponents on actors contains a category "Instance" that allows the user to connect a PCG Graph of their choosing to the PCGComponent which allows the Procedural Node Graph to sample the ...

If a child blueprint class has an Instanced/EditInlineNew object property, that property will always be detected as changed by the property editor (i.e. it will show a "Revert" arrow on that property), even if its properties are identical to the parent.

Context: Blueprint classes can use Instanced/EditInlineNew object property specifiers to create and edit subobjects directly in the editor. Problem: If a child blueprint class has an Instanced/Edit ...

DynamicMaterialParameters Niagara module resets write flags on emitter update

When using the DynamicMaterialParameters Niagara module in UE 5.6, 5.7, and UE5-Main (CL 50298778), updating an emitter causes Boolean values, such as Index0Float0Write, to reset to default values, ...

Crash when saving after resetting Instanced array element via Property Matrix on placed actors

When an Actor Component contains an Instanced UObject array marked EditDefaultsOnly, adding a new element to the Blueprint defaults correctly updates the Blueprint and its own Property Matrix. Howev ...

Ending a GameplayAbility from an AbilityTask created by the same GameplayAbility does not correctly end the AbilityTask, and it continues ticking.

When a GameplayAbility is ended from within a child AbilityTask, the AbilityTask is not cleaned up correctly. As a result, even though the GameplayAbility is no longer active, the AbilityTask contin ...