In UInstancedStaticMeshComponent, when some instances have near-zero scale, removing instances crashes the engine

UE - Rendering - Architecture - Oct 19, 2023

Class "UInstancedStaticMeshComponent" deliberately leaves null pointers in the "InstanceBodies" array of FBodyInstances. This can be seen in methods such as: [Engine\Source\Runtime\Engine\Private\I ...

NDisplay hangs and stops responding on cluster event send

UE - Virtual Production - nDisplay - Nov 12, 2019

"The test event is set up using the default CE port, but every time an event is sent through the launcher the display receives the input and processes it, however the launcher will "hang" and stop ...

Default subobject of dynamic component skips initial replication

UE - Networking - Sep 11, 2024

Because the component's subobjects are replicated before the component, the content block for the subobject is received before the component has been created on the client. Since this subobject is c ...

Refraction Depth Bias In Material Instances Not Updating to Parent Materials Value

UE - Rendering - Architecture - Materials - Aug 20, 2018

Refraction depth bias in Material Instances will not update to Parent Materials value. Found in 4.19 CL# 4033788, 4.20 CL# 4233996, and 4.21 CL# 4299102 Expected from user:Refraction Depth Bias sh ...

Linux editor can fail on start due to a stale TPS library in Engine/Binaries/Linux

UE - Platform - Linux - May 21, 2015

For 4.8, we moved LinuxNativeDialogs, a third-party library, to a different location (and also changed its API somewhat, so the old library is binary incompatible). However, some users apparently a ...

Unable to open UE4Editor on Linux - Bad hlslcc header found

UE - Platform - Linux - Nov 4, 2015

UE4Editor does not open on Ubuntu 15.10 due to the following error: [2015.11.04-16.19.35:974][ 0]LogOpenGLShaderCompiler:Error: Bad hlslcc header found! Missing '#'!Error in `./UE4Editor': free(): ...

ExponentialHeightFog is not rendering through VR

UE - Platform - Mobile - Mar 14, 2016

ExponentialHeightFog does not render for Gear VR devices when both the device and project are set for Gear VR. However, the fog does appear on a project without Gear VR enabled. Occurs On: GalaxyS6 ...

GetOverlappingActors/Components ignore physics actors spawned in with zero movement

OLD - Anim - May 15, 2017

GetOverlappingActors/Components ignore physics actors spawned in with zero movement. This only effects actors where the root is the DefaultSceneRoot and not the Static Mesh Component. User Descript ...

Crash after network disconnection/pulling network cable

UE - Networking - Jul 11, 2019

A very unfortunate bug shipped in 4.22 that causes a crash in many cases when a client is disconnected from the network, such as when unplugging the network cable. This will be a cert failure on con ...

'Get Tangent at Distance Along Spline' returns incorrect values compared to 'Get Location and Tangent at Spline Point'

Tools - Jul 18, 2018

The "Get Tangent at Distance Along Spline" node returns incorrect tangent values compared to "Get Location and Tangent at Spline Point", where the spline point is at the same distance along the path ...