Deferred spawned actors can receive BeginPlay before they are finished spawning

UE - Framework - Performance - May 18, 2023

Actors that are deferred spawned on BeginPlay can be added to the world while AWorldSettings::NotifyBeginPlay is still iterating the world's actors and dispatching BeginPlay. AActor::DispatchBeginPl ...

Mobile Previewer: Safe Zone Invalid Until Window Resize

UE - Platform - Mobile - Jul 12, 2021

When the Mobile Previewer loads, the Safe Zone widget is not working properly at startup, and requires a window resize to update to the correct Safe Zone. ...

Crash occur when loading AInstancedPlacementPartitionActor

UE - Editor - Workflow Systems - May 17, 2022

Crashes when loading an actor that inherits from AInstancedPlacementPartitionActor. There is a serialization size mismatch. ...

IOS crash disabling idle timer when closing the app

UE - Platform - Mobile - Apr 29, 2020

Licensee report of crash during shutdown due to setting [UIApplication sharedApplication].idleTimerDisabledbeing from the Game thread. Grouped together with others items in [Link Removed] ...

Custom UVs don't store information properly in layered materials.

UE - Rendering Architecture - Materials - May 9, 2022

[Link Removed] I have this set up so that FX artists can stack UV manipulations, so I don't want to just have all the UV manipulation in the layer with the base color, even though that does give me ...

Alembic Geometry Cache crash with multiple meshes

OLD - Anim - Sep 1, 2016

Importing an Alembic geometry cache will cause a crash with multiple assets. Test asset attached that can reproduce this. When I tried with a couple of simple shapes from 3Ds Max I did not get the ...

ACineCameraAttachMount's "Target Actor" constraint does not work with Spawnables or Replaceables in Sequencer

UE - Virtual Production - Tools - Virtual Camera - Aug 12, 2025

Constraints (UTickableConstraint) are usually created throuh the "Animation" tab available in the Editor's "Animation Mode". When created through that interface while Sequencer is open, the internal ...

Crash: Nativized AnimBP instances can assert on load in a cooked build with async loading enabled.

UE - Gameplay - Blueprint - May 9, 2019

This is a regression that was introduced alongside a memory optimization for Animation Blueprint assets. Suggested workarounds:Disable "Async Loading Thread Enabled" ORDisable Blueprint nativizati ...

MetalRHI Asserts When Using "Profile GPU" With RHI-Thread/Parallel-Execution

UE - Graphics Features - Sep 14, 2016

When the RHI thread is enabled (with or without parallel-execution) for Metal it isn't currently possible to run "profilegpu" because the GPU timestamp emulation code isn't multi-thread safe and pro ...

Crash in FVulkanLinuxPlatform

UE - Platform - Linux - Apr 17, 2019

Using the command in the repro steps on Linux will cause the Editor to crash and CrashReporter to pop up with a callstack. This behaves differently when tried on Windows with -vulkan. The project ...