Blueprint Array/Map properties with DefaultToInstanced types are not instanced properly

UE - Gameplay - Blueprint - May 6, 2019

At a licensee, I discovered a problem where Blueprint-created array and map properties are not correctly propagating the ContainsInstancedReferenced property flag. This means that if you create a Ma ...

Missing SmallOSAlloc/Free memory tracking with LLM on iOS

UE - Platform - Mobile - Dec 11, 2020

Licensee reports missing memory tracking for LLM on iOS: In Engine/Source/Runtime/Core/Private/HAL/MallocBinned.cpp in SmallOSAlloc, there is a compiler define for IOS and within it there is an LLM ...

Default subobject of dynamic component skips initial replication

UE - Networking - Sep 11, 2024

Because the component's subobjects are replicated before the component, the content block for the subobject is received before the component has been created on the client. Since this subobject is c ...

The ChaosCacheManager changes the bSimulatePhysics flag from the ObservedComponents and, if deleted, the change will persist, what can lead to confusion as observed physical entities will inadvertently stop simulating physics

UE - Simulation - Physics - Nov 26, 2024

The ChaosCacheManager (CCM) changes the bSimulatePhysics flag from the ObservedComponents and, if deleted, the change will persist, what can lead to confusion as observed physical entities will inad ...

AsyncSaveGameToSlotForLocalPlayer does not properly handle multiple requests

UE - Gameplay - Nov 14, 2025

ULocalPlayerSaveGame::AsyncSaveGameToSlotForLocalPlayer was designed to properly support multiple in flight requests at the same time, but the current code does not work correctly and this can cause ...

Default UE splash logo appears briefly when launching an application with an alternate launch image on iOS

UE - Platform - Mobile - Sep 15, 2020

Various users have reported seeing the default UE splash logo appear briefly before their custom launch screen appears. This was reported to have been seen in 4.25, and did not occur for users in 4. ...

MaxChannels (Voices) is printed incorrectly to the Output Log on new projects

UE - Audio - Mar 16, 2022

The Max Channels (voices) setting displays in the output log as 0 on new projects. Likely a result of [Link Removed]. Issue is in display only (there are 32 voices), but should ideally report the de ...

UnrealVS: Compile Single File no longer working after upgrading to 5.3

UE - Foundation - Cpp Tools - UnrealVS - Oct 2, 2023

After installing the UnrealVS version that arrived with 5.3. I can no longer use CompileSingleFile. It does however work on the Lyra project. One difference I notived, however, is that Lyra seems to ...

FAnimationRuntime::BlendPosesPerBoneFilter() causes an assertive crash when Skeletal Mesh LOD is changed

UE - Anim - Runtime - Nov 1, 2023

The crash occurs from "check(BoneBlendWeights.Num() == NumBones);" This crash occurs when the following conditions are met;The skeletal mesh LOD is changed.The number of bones is difference between ...

A LevelSequence will lose the binding to objects contained in a level instanced inside another level

UE - World Creation - Worldbuilding Tools - Level Instances - Sep 15, 2025

A LevelSequence will lose the binding to objects contained in a level instanced inside another level on 5.6 and up. Refer to the reproduction steps or the shared repro project provided by the licens ...