r.Shaders.Optimize=0 crashes when compiling a UI material

UE - Rendering - Architecture - Materials - Sep 2, 2024

[2024.08.30-22.12.22:384][ 73]LogWindows: Error: appError called: Assertion failed: CurrentGPUVirtualAddress != 0 [Link Removed] [Line: 659] Disabling shader optimisation can crash the editor when ...

Assert when having too many VR devices

UE - Platform - XR - Aug 31, 2018

Internal team is encountering a crash when adding too many VR devices. Email thread titled "Re: Crash Logs" The bug is an internal limit of devices the code supports, which is 8. If a controller o ...

Landscape LOD behaviours is not working as expected (Its Calculation is not based on Sections anymore)

UE - Graphics Tools - Terrain - Landscape - Apr 10, 2024

"Components can optionally be divided into either 1 or 4 (2x2) subsections to increase the resolution of the Landscape. These subsections are the base unit of Landscape LOD calculation." From Doc ...

The engine crashes when adding a new brush at newly created level by a specific way.

UE - LD & Modeling - Modeling Tools - Mesh Editing - Jun 17, 2019

issuesFBSPOps::csgAddOperation returns null if BuilderBrush has no valid polys.The creating level on content browser never calls "UEditorEngine::InitBuilderBrush(NewWorld);". But "New level" button o ...

Updating C++ projects with Marketplace plugins in 4.25.2 fails to build project

UE - Foundation - Cpp Tools - Plugin System - Jul 24, 2020

Projects created in previous engine versions fail to build in 4.25.2Running D:/Epic Games/UE_4.25/Engine/Binaries/DotNET/UnrealBuildTool.exe Development Win64 -Project="D:/Unreal Projects/MyProject4 ...

Upgrading project results in loss of game input

UE - Gameplay - Input - Jan 7, 2020

Upgrading a marketplace creator's project to engine version 4.23.1 and above results in loss of (previously) working functionality with game input. ProjectDownload: [Link Removed] Tested in: 4.2 ...

BP hierarchy change triggers incorrect map actor load warning: AttachTo: '{0}' is not static {1}, cannot attach '{2}' which is static to it.

UE - Framework - Blueprint - Apr 11, 2024

When a blueprint's component hierarchy is changed by changing a child component's mobility value to Static while deleting its parent component which has Movable mobility, levels saved with an outdat ...

FLowLevelMemTracker::GetTagAmountForTracker with CustomProjectTag returns 0 always

UE - Foundation - Core - May 7, 2020

FLowLevelMemTracker::GetTagAmountForTracker with CustomProjectTag returns 0 always. Because of FLLMTracker::FLLMThreadState::GetFrameStatTotals don't amount to about CustomTags. Following code will ...

Sequencer custom task scheduler hangs with more than 512 tasks (TDynamicSparseBitSet::IsBitSet and operator|=)

UE - ACT Character - Sequencer - Oct 12, 2026

With Sequencer.CustomTaskScheduling enabled, a task graph with more than 512 tasks can hang FEntitySystemScheduler::ExecuteTasks. Reported by a licensee, they hit it with a 528 task graph under Clan ...

Apex Cloth gets crazy after upgrade to 4.14

UE - Simulation - Physics - Dec 22, 2016

It has no this issue if only open previous cloth assets in 4.14The issue happens only if reimporting or updating the .apx or .apb and assign to the material slotReimporting both FBX skeletalmesh file ...