Unreal Engine Issues

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 ...

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 ...

Data loss with subobjects in Blueprint arrays

CreateDynamicMaterialInstance will pull from the base rather than overridden mesh on SkinnedMeshComponent when run from construction script

When UPrimitiveComponent::CreateDynamicMaterialInstance is called on a skinned mesh, and the input material is invalid, we call USkinnedMeshComponent::GetMaterial to get the base material on the exi ...

MakeArray wildcard node gives a compilation error when being used in a Blueprint Macro.

There is an error with the SmartMacroInterface, where you can't use an empty wildcard "Make Array" node. This error makes the blueprint not compile and the macro unusable. Disabling the bUseSimpleWi ...

ExposeOnSpawn pins no longer read default values from the linked class

This is technically a regression that was introduced in 5.5. This was intentionally changed in order to address a separate issue [Link Removed]. Additionally, this makes it explicit that the exposed ...

Circularly referenced blueprints cause stack overflow in a package game without IOStore

Editor crashes when the "Find in Blueprints" dialog runs its indexing task after any SlowTask was canceled by the user

If any SlowTask is canceled by the Editor's user, and later on the "Find in Blueprints" dialog is opened and needs to perform its async indexing task, the Editor crashes on thread FAsyncSearchIndexT ...

In class UCancellableAsyncAction, methods IsRegistered() and ShouldBroadcastDelegates() still return true after Cancel() or SetReadyToDestroy() unregisters the object.

Class UBlueprintAsyncActionBase provides methods RegisterWithGameInstance() and SetReadyToDestroy(), which respectively register and unregister the object with the game instance. Derived class UCanc ...

In Editor, Blueprint resources are not freed up when the Blueprint is closed

It appears that the preview scene used to render thumbnails is not destroyed after a thumbnail is rendered, even after the blueprint editor is closed and GC is run. Also found in Release-5.4, CL: 31 ...