UNetDriver server-side hitch results in ActorInfo->NextUpdateTime far into future

UE - Networking - Feb 16, 2024

A high UWorld::Tick DeltaSeconds (i.e. GameThread hitch) results in a high UNetDriver::TickFlush DeltaSeconds. This DeltaSeconds can high (many seconds) if the hitch is long. This value then affects ...

Navmesh doesn't work in a Packaged Build if it was placed in a Sublevel

UE - AI - Oct 19, 2018

Once packaged, a persistent level is unable to create navmesh data properly if the navmesh bounds volumes are only present in its sublevels. The issue can be traced to the UNavigationSystemV1::IsThe ...

Crash Opening Editor with Vulkan - Fatal Error - RenderingThread.cpp

UE - Rendering Architecture - RHI - Mar 15, 2019

Editor crashes when opening to project browser on Linux. Fatal error: [File:D:\Build\++UE4\Sync\Engine\Source\Runtime\RenderCore\Private\RenderingThread.cpp] [Line: 819] Rendering thread exceptio ...

Changes to Instanced Properties default value on BP not propagated to placed actors in the opened level

UE - Foundation - May 15, 2025

In UE versions 5.4 and onwards (as of CL 42589677 in Main), when an Instanced UObject property is defined in an Actor Blueprint, modifying the default value in the Blueprint does not propagate the c ...

Node Comments don't appear until the node is scrolled over after it is entered

UE - Gameplay - Blueprint - Nov 23, 2016

Node Comments don't appear until the node is scrolled over after it is entered This is a Regression. It was working in 4.13.2 but broken in 4.14. User Description: BP node comments hidden until m ...

Yaw input is not always applied as expected depending on whether the yaw input function is called in the Player Controller Blueprint vs in the Character Blueprint

UE - Gameplay - Blueprint - Nov 20, 2018

In the attached project, the controller Blueprint is set to apply rotation based on a pair of bool values indicating whether the A (Rotate Left) or D (Rotate Right) keys are pressed. The controller ...

App fails to open on Android: Assertion failed referencing LaunchAndroid.cpp:415

UE - Editor - Content Pipeline - Datasmith - Importer - Oct 11, 2018

AR App fails to open on Android: Assertion failed referencing LaunchAndroid.cpp:415 when Unreal Datasmith is installed.10-11 11:22:57.499: D/UE4(18917): LogAndroid: Error: Assertion failed: false [F ...

[CrashReport] UE4Editor_Landscape!ALandscapeProxy::PostEditChangeProperty() [landscapeedit.cpp:3692]

UE - LD & Modeling - Terrain - Landscape - Jul 19, 2017

This is a common crash affecting users in 4.16. Unfortunately they have not provided any additional details. Source Context 3684 // Remove null layer infos 3685 EditorLayerSettings ...

[CrashReport] FGenericPlatformMemory::OnOutOfMemory | TArray<FCompressedChunk,FDefaultAllocator>::ResizeTo

UE - Foundation - Core - Jul 20, 2017

This is a common crash affecting users in 4.16, and has occurred since at least 4.12 for more than 200 unique users. The callstack has similarities to [Link Removed], and as-such may be out of our ...

Costs of Static Lights on Render Thread

UE - Graphics Features - Jun 9, 2016

A Japanese developer's making a scene that has over 4000 static point lights. They thought the lights don't affect rendering in runtime. But they realized the RenderThread's costs become bigger. I ...