Unreal Engine Issues
Unreal Engine Issues
Material parameters flickering due to UMG animation switching and multi-threaded execution
UE - AI Workflows - UI Systems - UMG - May 12, 2026When continuously transitioning to UMG animations that have a track targeting the same material parameter within the UUserWidget::OnAnimationFinished event, the number of source inputs to UMovieScen ...
GAS: Ability that destroys owning actor on activate causes crashes due to ABILITYLIST_SCOPE_LOCK
UE - Gameplay - Gameplay Ability System - Oct 31, 2023A GameplayAbility that destroys its owning actor inside ActivateAbility() causes a crash, because actor destruction will modify the ability list but ActivateAbility() is called within an ABILITYLIST ...
shadow seam occurs when lighting is built after object is rotated
UE - Graphics Features - Jul 12, 2017There is an issue that is occurring where visible shadow seams appear after an object is rotated where it was not previously. CL tested 4.15.3 - CL 3450819 - Issue is present 4.16.2 - CL 3514769 - ...
Cannot undo moving a mesh via Pilot
Tools - Jan 2, 2018There is an issue where the undo does not affect movement made by piloting an object in a level. This issue does not appear to be a regression. Versions Tested: This issue occurs in all versions te ...
[AI] Nav Modifier Volume inside of a Level Instance does not update navmesh when moved
UE - Runtime - Character - Oct 3, 2023The issue is seen when using a normal navmesh inside of a World Partitioned level. Adding a Nav Modifier Volume to a Level Instance, and placing the Level Instance in the world will affect the navme ...
This project crashes when one Blueprint is compiled if its child Blueprint is opened in another tab
UE - Gameplay - Blueprint - Mar 18, 2015This project crashes when one Blueprint is compiled if its child Blueprint is opened in another tab. This only occurs with one Parent/Child combination: the crash occurs when compiling Building whil ...
Editor hits Asserts when trying to use debug rendering such as ShowFlag.LODColoration
UE - Rendering - Architecture - RHI - Sep 22, 2020The assert in BasePassRendering.cpp:693 fires, crashing to desktop when using this console command in the editor, in PIE, and closes out the window when playing in Standalone. Does not crash when us ...
Light Propagation Volume Occlusion Intensity not working as intended
UE - Graphics Features - Oct 26, 2017Light Propagation Volume Occlusion does not affect scene as it should. The workaround in 4.17.2 is to disable DBuffer decals which will enable the Light Propagation Volume Occlusion. Occurs in 4.1 ...
[CrashReport] UE4Editor_BlueprintGraph!BlueprintActionFilterImpl::IsEventUnimplementable() [blueprintactionfilter.cpp:588]
UE - Gameplay - Blueprint - Jun 1, 2016This crash has been reported through the 4.12 Previews and is continuing to occur in the 4.12.0 release. Additional information about this crash is not available at this time, however it may be the ...
Starter Content Blueprint_Effect_Explosion Root Componet In Invalid State
UE - Content - Feature Pack - Sep 22, 2023The Blueprint_Effect_Explosion Actor's Root Component in the Starter Content is in some form of invalid state. It reports to have a scale of (1.0, 1.0, 1.0) in the details panel but further behaviou ...