"Enabled per poly collision" under "Support compute skincache" is ON causes a crash at runtime

UE - Simulation - Physics - Aug 16, 2018

It seems that "Enabled per poly collision" with "Support compute skincache" causes a crash at runtime immediately. We can easily reproduce it with ContentExample. The logs at the crash timing... L ...

TSparseArray NatVis visualizer doesn't work for arrays that use TInlineSparseArrayAllocator

UE - Foundation - Cpp Tools - Nov 6, 2025

The NatVis visualizer allows many custom Unreal types to be displayed in a helpful manner inside the Visual Studio watch window. One such type is TSparseArray. Under normal circumstances, visualizin ...

Crash After Reimporting Static Mesh With Added Material Slot

Tools - Jan 12, 2017

After importing a mesh without any materials assigned, if you add a material slot and save the material. Reimporting this mesh will cause a crash. The only way to avoid this crash is to import a me ...

Possession is not replicated properly to some clients

UE - Networking - Nov 8, 2018

A user has reported an issue where Possession replication or Character Movement replication, unsure of which, is not working properly for some clients. It seems to work fine for the first client but ...

Attempting to set a new PIE window to Windowed Fullscreen mode causes both the new PIE window and the original Editor window to freeze and stop accepting input

UE - Platform - Apple - Dec 24, 2018

When starting PIE in a New Editor Window on a Mac, the both the new window and original Editor window will freeze and stop responding to inputs if an attempt is made to change the window to Windowed ...

NormalizePackageNames() should interpret 'exclude developer folders' to also exclude packages in ExternalActors and ExternalObjects

UE - CoreTech - Oct 14, 2022

In NormalizePackageNames() (PackageUtilities.cpp), there is a PackageFilter parameter, which can be set to exclude developer packages (NORMALIZE_ExcludeDeveloperPackages). The code only checks the b ...

Disabling Grid ShowFlag also hides billboard sprites and volume outlines

UE - Graphics Features - Nov 8, 2023

The following odd behavior did not happen until UE 5.2, but happens in the latest UE 5.3. When the "Grid" show flag is disabled in the Level Editor Viewport, all billboard sprites and volume outlin ...

MRQ GBuffer Output Renders Normal GBuffer instead of BaseColor

UE - Virtual Production - Tools - MRQ - Feb 27, 2025

When attempting to use console variables to render the BaseColor output, the GBuffer overview or GBuffer normal output is rendered instead.  Using the commands in the Editor viewport shows the BaseC ...

VALIDATE_UNIFORM_BUFFER_LIFETIME fails compilation

UE - Graphics Features - Jul 24, 2025

Also verified on Release-5.5.4 CL 40574608 ...

Subsurface Profile Materials That Are Illuminated By Particle Lights Render White

UE - Graphics Features - Feb 9, 2017

Due to the changes made to subsurface profile (implementation of full resolution skin shading) it now renders white or with heavily faded base colors under certain conditions. In this case it is wh ...