AnimNotify serialization crash in editor

UE - Anim - Runtime - Mar 15, 2026

The crash is caused by changing the variable type of an AnimNotify that is already referenced by a montage. This issue cannot be reproduced in 5.6. ...

UAbilityTask_SpawnActor::BeginSpawningActor may return true when SpawnedActor contains stale value

UE - Foundation - Mar 15, 2026

UAbilityTask_SpawnActor::BeginSpawningActor assumes the incoming AActor*& SpawnedActor parameter is nullptr if no actor was spawned, but it does not initialize the parameter at the start of the func ...

GroomComponent: SetVisibility(false) causes per-frame simulation reset instead of stopping it

UE - Simulation - Visual - Mar 12, 2026

UGroomComponent::TickComponent sets bResetSimulation = true every frame when the component is not visible. This causes NiagaraDataInterfaceHairStrands to triggering a full simulation reset every fra ...

NDC Sorting Incorrect

UE - Niagara - Mar 12, 2026

Using the new NDC BP nodes in 5.7 causes sorting to break; one system, regardless of world placement, is always drawn over the other. Even when the viewpoint puts the dominant system in the foregrou ...

Distance Field Ambient Occlusion artifacts when using dynamic resolution

UE - Rendering - Graphics Features - Mar 12, 2026

Distance Field Ambient Occlusion produces artifacts when using Dynamic Resolution at lower framerates. ...

State Tree Reselecting State Using Stale Event Data

UE - AI - StateTree - Mar 12, 2026

When a state tree tries to reenter a state that requires an event with payload data, on re-entry the payload data will contain the same value as the first entry, even if the event sent had payload d ...

Material expression "FloatToUInt" can trigger a check() when input is invalid

UE - Rendering - Architecture - Materials - Mar 11, 2026

When a "Float to UInt" Expression is used in a Material Graph with a valid direct input connection that fails to evaluate, function UMaterialExpressionFloatToUInt::Compile() does not catch the input ...