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 ...
Enabling ZenLoader causes editor crash when undoing Level Instance deletion
UE - Core - Systems - 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 ...
Instigator is no longer automatically set when spawning actors from blueprint
UE - Framework - 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 ...
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 - Runtime - Mutable - Mar 31, 2026FCustomizableInstanceDetails::FillChildrenMap() unconditionally registers parent-child relationships via __ParentParamName metadata without verifying the parent exists in the active parameter list. ...
Instanced static meshes fire an erroneous performance assert about loose parameters.
UE - Graphics Features - Sep 4, 2019"This ensure is intended to catch regressions where rendering programmers add a loose parameter to LocalVertexFactory, breaking dynamic instancing on regular static meshes. InstancedStaticMeshes c ...
Translucent Wireframe Materials Exhibit TSR Aliasing/Crawling Due To Incorrect Velocity Rendering When Set to Output Depth And Velocity
UE - Rendering - 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 ...
editor crashes when variable inside of a struct is set to a class type then the object is moved to a new folder
UE - Gameplay - Blueprint - Mar 17, 2015If a struct has a variable set to a class type, then the object of that class type is moved to a new folder in the editor, the struct will replace the class type with "class", which causes the edito ...
UMG: RetainerBox with zero-size child returns incorrect LayerId on OnPaint()
UE - AI Workflows - UI Systems - Nov 4, 2025When a RetainerBox contains a child that for some reason has a desired size of zero, its OnPaint() method can incorrectly return LayerId 0. Afterwards, widgets further down the hierarchy can base th ...