Unreal Engine Issues
Unreal Engine Issues
Regression: FAnimInstanceProxy memory leak when BeginDestroy() called on UAnimInstance before USkeletalMeshComponent
UE - Runtime - Animation - Feb 10, 2025In UE 5.5, the fix applied by CL 36529858 in ue5-main updated USkeletalMeshComponent::ClearAnimScriptInstance() to call AnimScriptInstance::UninitializeAnimation() on the animation instance. This, i ...
Instigator is no longer automatically set when spawning actors from blueprint
UE - Gameplay - Blueprint - Aug 20, 2024Actors that are spawned from blueprints will no longer have their instigator automatically set to the instigator that spawned them. This is a regression in 5.5, because in 5.4 and earlier a null Ins ...
Enabling ZenLoader causes editor crash when undoing Level Instance deletion
UE - CoreTech - Sep 5, 2024Crash reported through UDN. With ZenLoader enabled, deleting a level instance and triggering Undo causes a crash in ULandscapeComponent::PostEditUndo() The user has provided an example project th ...
World Memory Leaks crash with a hidden sublevel to a redirector
Tools - Dec 8, 2020From UDN: The reason it crashes is because Child doesn't get garbage collected, which is because it still has the RF_Standalone flag. UEditorEngine::EditorDestroyWorld clears RF_Standalone flag ...
Mutable: Child parameters hidden when intermediate Object Group uses "All Options"
UE - Anim - Mutable - Mar 31, 2026FCustomizableInstanceDetails::FillChildrenMap() unconditionally registers parent-child relationships via __ParentParamName metadata without verifying the parent exists in the active parameter list. ...
Translucent Wireframe Materials Exhibit TSR Aliasing/Crawling Due To Incorrect Velocity Rendering When Set to Output Depth And Velocity
UE - Rendering - Graphics Features - Nov 27, 2025Note that this bug potentially also affects a wide variety of material / geometry setups; however, a translucent wireframe setup is currently the main reproduction case. The issue may also be notice ...
GameInstance and subsystem initialization order is incorrect for Play In Editor
UE - Gameplay - May 18, 2023The order of world and game instance initialization is different between a true standalone game (cooked game or an editor build with -game) and a Play In Editor game. Specifically, in Play in Editor ...
Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key causes a memory leak
UE - Framework - Blueprint - Apr 15, 2025When 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 ...
Distributed HLOD builds always fail for projects not under the Engine Root
UE - World Creation - Worldbuilding Tools - HLOD - Dec 4, 2024In BuildProject.txt, to make relative path to the project outside the engine root, all paths contains “..” after action command directory. D:/dev/UnrealEngine-5.5.0//HLODTemp/f09bf0f5/HLODBuilder0 ...
[AI] Debug Render Scene Proxy hits ensure for registering a delegate twice during level streaming.
UE - AI - Debugging - Aug 31, 2022Description from licensee: We're seeing an ensure get tripped up in FDebugRenderSceneProxy that says "DrawDelegate is already Registered!". Debugging the issue, we have confirmed that the DrawDeleg ...