Unreal Engine Issues
Unreal Engine Issues
[5.4+] World Partition Landscape Spline Meshes Builder - Source landscape splines are not properly removed/hidden
UE - Engine Scaling - Streaming - HLOD - May 30, 2025LandscapeSplineActors and LandscapeSplineMeshesActors are not behaving as expected in 5.4 or 5.5. Testing in 5.4 the issue mostly seems to stem from issues with the Target Landscape -> Landscape Ac ...
FMassMoveTargetFragment::CreateNewAction does not update PreviousAction, breaking the start-of-path avoidance fade and related behavior for MassEntity crowds
UE - Runtime - Character - Jul 28, 2026In MassEntity-based crowds, when an agent transitions from Stand to Move and begins walking, the Avoidance trait parameters StartOfPathDuration and StartOfPathAvoidanceScale, which are meant to temp ...
[CrashReport] Mac crash - libobjc.A.dylib!objc_retain() [UnknownFile]
UE - Platform - Apple - Nov 10, 2017This is a longstanding but low frequency Mac crash. User DescriptionsChanging camera shake values and testing in a new editor window Callstack from Log[2017.11.09-19.23.22:392][ 63]LogMaterial: Mi ...
BlendSpace Loop Boundary Produces Inconsistent Sync Marker Data andTriggers an AnimSequence Follower Assertion
UE - Runtime - Animation - Jul 22, 2026Summary In UE 5.7.4, when a looping BlendSpace with Match Sync Phases enabled plays as a SyncGroup Leader and crosses its loop boundary during a transition to an external AnimSequenceFollower in th ...
Niagara Scalability Crash When Processing Significance
UE - Rendering - Architecture - Niagara - Jun 4, 2025Method FNiagaraScalabilityManager::ProcessSignificance() iterates on indices from Context.SignificanceIndices and uses them to access the State and ManagedComponents arrays. It can then decide to cr ...
[Enhanced Input] Chord trigger fails when its referenced action lives in a lower-priority IMC
UE - Gameplay - Input - May 18, 2026Summary A UInputTriggerChordAction does not fire when the action it references (the "chording action") is mapped in a different Input Mapping Context with a lower priority than the IMC containing the ...
Data Asset Instances created from Blueprints and are not selectable in asset pickers until their parent Blueprint is loaded. They are also not displayed correctly in the Content Browser
UE - Framework - Blueprint - Sep 3, 2024Consider a C++/BP class containing an EditAnywhere/InstanceEditable variable with type (UDataAsset*), (UPrimaryDataAsset*), or any of their subclasses. When setting this variable using a Property Ed ...
Crash when opening a texture or editing its properties after stopping a preview in the material editor
UE - Rendering - Architecture - Materials - Sep 5, 2025When a texture asset has certain properties edited, its PostEditChangeProperty() method calls to UTexture::NotifyMaterials(), which triggers a recompilation of materials that reference it in their m ...
Crash when upgrading Nvidia GFX driver from Version 457.85 with open Project
UE - Rendering - Features - Nov 18, 2022Repro Rate: 5/5 Summary: When opening a Project in UE version 5.1.0 with Nvidia GFX driver version ###, the user is notified that there are known issues with this driver through a pop-up:WARNING: K ...
Illegal reference to private object when cooking a child level sequence with a time warp track
zComponent - Archive - Apr 28, 2025Slack: [Link Removed] Another Slack: [Link Removed] Cook error:UATHelper: Cooking (Windows): LogSavePackage: Warning: UATHelper: Cooking (Windows): Referencers of MovieSceneTimeWarpSection /Gam ...