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 ...

Sub-world partitions do not properly handle partial editor loading as world partition standalone level instances' spatially loaded actors do not get loaded even when the Level Instance is force loaded or loaded in by region.

UE - World Creation - Worldbuilding Tools - World Partition - Aug 19, 2025

Context Level Instancing is a level-based workflow designed to improve and streamline the level editing experience. In a standalone Level Behavior, when the Level Instance Actor is loaded through it ...

Editor reports crashes and terminates for exceptions that would otherwise be cleared by structured exception handlers

UE - Foundation - Core - CrashReportClient - Jun 8, 2020

In 4.25.1, I added a vectored exception handler to capture unhandled exceptions to the Editor process. This handler runs too soon. It doesn't let the structured exception handlers run first where ma ...

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 ...

Pasted material function nodes lose their connections

UE - Rendering Architecture - Materials - Dec 3, 2019

The fix for [Link Removed] caused a regression where links to material nodes no longer carry over when a group of nodes is copied and pasted ~ User submitted Image and repro steps appended. I conf ...

Solidworks exporter installation does not proceed

UE - Editor - Content Pipeline - Datasmith - Exporters - Dec 9, 2021

3 users reported the same issue. DEBUG: Error 2203: Database: 1031. Cannot open database file. System error -2147287038  or DEBUG: Error 2203: Database: 1036. Cannot open database file. System err ...

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 ...

Camera Switcher Import option not functioning properly

UE - Anim - Sequencer - Oct 22, 2019

In UE 4.20 we got a feature that let you import a FBX file that contains cameras with a camereaswitcher to create a "camera cut track" within sequencer. From the release notes of 4.20: https://docs ...

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 ...