UAIPerceptionSystem::Tick() has a chance of not being called after level reloading

UE - AI - Dec 16, 2019

UAIPerceptionSystem::Tick() is not called after level reloading. When Debugging, UAIPerceptionSystem::CurrentTime is always 0, and UAIPerceptionSystem::SourcesToRegister always contains sources to ...

Complex collision mesh might lose its collision in the editor

UE - LD & Modeling - Modeling Tools - Mesh Editing - Feb 18, 2020

This is affected by loading order. In the case, display mesh was loaded firstly and try to build collision mesh form complex collision mesh asset. But the collision mesh didn't finished to make Ren ...

Crash if the setting of PhysicalAnimationComponent is changed in the same frame as teleport processing

UE - Simulation - Physics - Apr 24, 2020

Crash when ApplyPhysicalAnimationProfileBelow node and UPhysicalAnimationComponent :: UpdateTargetActors by UPhysicalAnimationComponent :: OnTeleport run in the same frame. Because RuntimeInstanceDa ...

Crash calling destroy actor for Geometry Collection while it's simulating

UE - Simulation - Physics - Destruction - May 12, 2020

Crash occurs when user call Destroy Actor on a Geometry Collection Actor. This seems to only occur while the actor is simulating. If called while on the ground, it doesn't seem to occur. ...

Moving actor to another level breaks soft object reference

UE - Gameplay - Jun 9, 2020

REGRESSION: In 4.24, there was a fixup process that would allow the soft reference to remain valid. This seems to be missing in 4.25 Moving an actor to another sublevel immediately breaks soft ref ...

Actors are not properly restored when undoing a Replace Selected Actors transaction

UE - Gameplay - Components - Jul 22, 2020

When undoing a Replace Selected Actors operation, the resulting actor is corrupt and triggers an ensure where the root component is in the process of being destroyed. This is a regression that poppe ...

Crash after creating a suboject for RootComponent if the actor is placed on the level

UE - Foundation - Cpp Tools - Hot Reload - Nov 6, 2020

The crash occurs when trying to assign a new value to RootComponent if the Pawn is already placed on the level Crash does not happen in  P4 //UE4/Release-4.25.3 CL 13942748 Other steps to reproduc ...

Crash when copying and making a button widget the root of a second widget blueprint

UE - Editor - UI Systems - Apr 13, 2021

Pasting a button element from one Widget Blueprint into a second Widget Blueprint that has had its root Canvas Panel deleted results in a crash. The crash only occurs when the Canvas Panel is delete ...

OSS Steam: SteamSocket listen connections do not work after poll group changes

UE - Online - Oct 25, 2021

In 4.27 the logic in SteamSocket.cpp which is part of the SteamSockets plugin was changed to use Poll Groups instead of a removed API function that checked all children of a listen socket. However,  ...

Report of branching point notifies failing to trigger

UE - Anim - Runtime - Nov 15, 2021

The problem seems to come from a notify having its LinkedMontage set to null when RefreshBranchingPointMarkers() is called. IsBranchingPoint() fails in this case, so it's never registered as a branc ...