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 ...

[CrashReport] Crash related to movie render - UE4Editor_UnrealEd!UEditorEngine::Tick()

UE - Anim - Sequencer - Jun 22, 2017

This is a common crash occurring for users in the 4.15 and 4.16 releases. It seems related to rendering movies in Sequencer, but additional information is currently unavailable. A log file is attac ...

[CrashReport] Assertion failed: NewWorld | UE4Editor_Engine!UEngine::LoadMap()

UE - Gameplay - Nov 2, 2017

This is a common and longstanding crash that has occurred since at least 4.15. Originally this was being tracked under [Link Removed] due to sharing the same callstack, but that had specific repro ...

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 ...

Using a Wait Delay node on Linux causes editor to immediately close without crashing

UE - Platform - Linux - Sep 14, 2015

If a call is made to the blueprint node Wait Delay the editor will immediately close during PIE when the call is made without the crash reporter appearing. The "Wait Delay" node only exists on Linu ...

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 ...

Translucent Materials and Atmospheric Fog Appear Black or Pink on Mac

UE - Graphics Features - Jan 3, 2018

I tested this on a Mac Pro in UE 4.15, 4.16, 4.17, and 4.18. As a possible workaround for the fog issue, I've discovered that setting Atmospheric Fog > Lighting > Disable Ground Scatter to "True" wi ...

Large Landscapes cause long PIE start time delays

UE - LD & Modeling - Terrain - Landscape - Jan 29, 2020

These delays appear with large Landscapes (for example 8029 x 8029) . The delays only start occurring after the level is saved and reopened. After which PIE start times will be 5 to 15 times longer ...

Some Planar Reflections not working on more than one surface if it's a single mesh

UE - Graphics Features - Nov 2, 2016

Planar Reflections only work with a single surface or limited surfaces when it's a single mesh vs multiple meshes making up the piece. Attached is a sample project that will show the issue. Level ...