Unreal Engine Issues
Unreal Engine Issues
UAnimNotify::Notify not called during USkeletalMeshComponent interaction with UPhysicsControlComponent when PhysicsBlendWeight is zero
UE - Anim - Synthesis - Physics Control - Mar 30, 2025UAnimNotify::Notify not called during USkeletalMeshComponent interaction with UPhysicsControlComponent when PhysicsBlendWeight is zero. The licensee has provided his analysis of the code: If USkelet ...
Large Landscapes cause long PIE start time delays
UE - LD & Modeling - Terrain - Landscape - Jan 29, 2020These delays appear with large Landscapes (for example 8029 x 8029) . The delays only start occurring after the level is saved and reopened. After which PIE start times will be 5 to 15 times longer ...
[AI] Bad entries in NavigationRepository for Box collision with bCanEverAffectNavigation set to false
UE - AI - Navigation - Oct 26, 2025Some components continue to dirty the navigation state even if bCanEverAffectNavigation is unchecked. Behavior appears very similar to an existing bug, [Link Removed] ([Link Removed]), which invol ...
Crash rendering image sequence if the Sub-Level with matinee is not loaded
Tools - Apr 15, 2016Crash rendering image sequence if the Sub-Level containing the matinee is not loaded. This seems to go away if the level is either set to "Always Loaded". Seems to be a result of people not switch ...
Crash when editing members of a struct contained within a UObject instanced inside a USceneComponent
UE - Editor - Jan 24, 2024When implementing a USceneComponent in C++, one may want to add one or more internal UObjects to hold some data or perform specific tasks (this is also done by several UE built-in components). These ...
Saving Behavior Tree with Blueprint task inheriting from native class invalidates Blackboard key when BP contains a function
UE - AI - Jul 8, 2025A regression introduced in UE 5.6 causes Blackboard key selectors in Blueprint tasks to become invalid when the Blueprint inherits from a native subclass of UBTTask_MoveTo (or UBTTask_BlackboardBase ...
FBX Import - 5.5.4 - Morph targets 1 frame offset
UE - Editor - Content Pipeline - FBX - Feb 17, 2025Morph targets work! Yay! But found another issue. Basically import an fbx with multiple animated morph targets applied to it. The morph change shape over 1 frame and for some reason in 5.5.4, there' ...
Mouse Not Functioning Correctly with Multiple Displays Connected to Mac
UE - Platform - Apple - Apr 24, 2015When using mutliple monitors connected to a Mac the mouse behavior does not function well. Attempting to navigate and drag windows to and from individual displays proves difficult. The user reporti ...
[CrashReport] Assertion failed: !bRequireNormalization - UE4Editor_Landscape!ULandscapeComponent::ReplaceLayer()
UE - LD & Modeling - Terrain - Landscape - Jul 19, 2017This is a common crash affecting users in 4.16, and has occurred since at least 4.14. Over 200 unique users have been affected, though they have provided little information. User DescriptionsI am a ...
Sampling textures with bias in the path of a custom data pin causes derivative operations when avoidable
UE - Rendering - Architecture - Materials - Apr 8, 2025Materials that make use of the analytical derivatives path to avoid hardware derivatives can still generate derivative operations on texture samples when the shading model has a custom data pin and ...