Lighting Channels Do Not Function with 78+ Lights on Actor

UE - Graphics Features - Oct 20, 2017

Lighting channels do not function when the number of lights affecting actors is 79 or higher. Any number of lights that is 78 or fewer will honor lighting channel assignments. ...

Setting multiple identical actors to replicate movement will crash on PIE with multiple players

UE - Networking - Jan 28, 2015

If ten or more of the same actor in a level have the "replicate movement" checkbox set to true, the editor will crash on PIE if the number of players is set to 2 (or with 1/2/3 players if dedicated ...

Editor crash when adding mesh renderer elements in Niagara

UE - Niagara - Jul 8, 2025

When adding multiple meshes to a Niagara Mesh Renderer Module, a check() will be triggered due to a mismatch in the number of Widgets and the number of Tooltip Widgets. ...

When importing multiple meshes at once and change the Uniform Scale meshes import at different sizes

UE - Editor - Content Pipeline - Import and Export - Sep 21, 2017

When a large quantity (about 50 in this case) are imported simultaneously, and the Import Uniform Scale is changed to any other number besides 1, random meshes differ in size. This happens regardles ...

Trying to chord two buttons already mapped to actions to fire a third action when both are actuated fails.

UE - Gameplay - Input - Apr 14, 2022

We're aiming to set up LT - action 1, RT - action 2, LT + RT - action 3 here. I don't think this is supported via chording at present. You'd need to handle it manually (probably via adding/removing ...

Emissive material lighting falloff regression in GPU Lightmass

UE - Graphics Features - Sep 12, 2023

Forum user noted that emissive lighting being built with GPU Lightmass is in fact being built, just not around the mesh, but in a larger radius and with reduced strength compared to 5.1.1. They foun ...

[CrashReport] UE4Editor_Engine!UGameViewportClient::Draw() [gameviewportclient.cpp:1170]

UE - Graphics Features - Apr 4, 2017

Was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Access violation - code c0000005 (first/seco ...

Fracture Mode > "Remove-On-Break" setting: Cluster Crumbling causes flickering

UE - Simulation - Physics - Destruction - May 10, 2025

Fracture Mode > "Remove-On-Break" setting: Cluster Crumbling causes flickering. Once the Remove-On-Break Cluster Crumbling effect is activated, there is a small delay between the disappearance of th ...

[CrashReport] UE4Editor_Engine!operator new<FBatchedLine,FDefaultAllocator>() [array.h:2812]

OLD - Anim - Jun 2, 2016

Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 804] Array index out of bounds: 175 from an array of size 171 Source Context: 2797 2798 temp ...

If shot track ends short of the Master Sequence length, all actors return to default state

UE - Anim - Sequencer - Oct 14, 2016

If shot track ends short of the Master Sequence length, all actors return to default state. This becomes an issue when you need the actors manipulated in Shot 1 to maintain their "end state" into s ...