Array index out of range with StopTree

UE - AI - Mar 26, 2019

Crashes when exiting PIE while executing multiple async tasks. By explicitly executing EndTask and FinishAbort of RecieveAbort, this caused by performing out-of-range in array access to InstanceStac ...

Niagara GPU Emitter Flickering at Certain Angles When the System Origin is Occluded

UE - Niagara - Mar 25, 2019

Niagara GPU Particle Flickering at Certain Angles When the System Origin is Occluded. Found in 4.20 CL# 4369336, 4.21 CL# 4753647, 4.22 Preview 6 CL# 5439949, and 4.23 CL# 5533539 ...

Niagara Mesh Renderer Incorrectly Rendering Mesh at Distances When Using Two Sided Material

UE - Niagara - Mar 25, 2019

Niagara Mesh Renderer Incorrectly Rendering Mesh at Distances When Using Two Sided Material.  Working as expected in 4.20 CL# 4369336 and 4.21 CL# 4753647 Found in 4.22 Preview 6 CL# 5439949 and 4 ...

ForceActorRelevantNextUpdate will only force an update on the first connection

UE - Networking - Mar 21, 2019

The ForceActorRelevantNextUpdate will only trigger an update on the first connection in the list. Note that the ForceActorRelevantNextUpdate does not work on dynamic actors since their ActorChannel ...

Editor will freeze if anim composite has an animation with a notify and length of 0

OLD - Anim - Mar 21, 2019

An anim composite will freeze the editor if one of its animation segments has a a notify and a length of 0 or less. Debugging shows that the engine is stuck inside UAnimSequenceBase::GetAnimNotifies ...

Setting spline in Niagara Override Parameters corrupts system after closing level

UE - Niagara - Mar 19, 2019

The USplineComponent appears to be corrupted. It will pass the null check, but operations done on the data cause the engine to crash. (See the linked UDN for more details) ...

Crash on loading pre-4.20 cloth data when compute skin cache is enabled in 4.21

UE - Graphics Features - Mar 19, 2019

According to information from the licensee, the else clause was added to "FSkeletalMeshLODModel::(GetClothMappingData()" at CL 4437969 , but if it is the cloth data existing from 4.20 or earlier, it ...

GetKnownPerceivedActors doesn't stop calling when specified AISense should be forgotten

UE - AI - Mar 17, 2019

There is a difference in implementation and set of checks that are made in GetKnownPerceivedActors() depending on if you use specific SenseClass or leave it as nullptr (so it will return info for al ...

Rounding errors are present in FJsonValue::TryGetNumber(int64&) and FMath::RoundHalfFromZero()

UE - Foundation - Core - Mar 8, 2019

A licensee reported a bug in rounding of a call to FJsonValue::TryGetNumber(int64&) with large values.  In investigating this, it appears that equivalent problems also exist in FMath:: rounding func ...

PoseAsset::GetAnimationPose Normalizing all bone rotations per track

OLD - Anim - Mar 6, 2019

In UPoseAsset::GetAnimationPose after the curves are blended the all out pose's rotations are normalized for each track instead of just the specific bone for that track (See linked UDN for more deta ...