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 ...

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 ...

Missing vegetation created via PCG on export

TM - Rendering - Feb 21, 2025

If you compare this 2 automation tests done on Swiss chalet project, you could see that some parts of vegetation are missing : [Link Removed] [Link Removed] The diff between the 2 exports is caus ...

Path Tracing denoiser is not stable in animation

UE - Graphics Features - Nov 30, 2021

When rendering an animation with the path tracer through MovieRenderQueue, at low sampling rates the denoiser produces splotchy results that flicker from frame to frame. The current denoiser (Ope ...

Swarm: Not able to set number of processors to use for Swarm from the UI

UE - Graphics Features - Aug 25, 2015

There is a setting called "LocalJobsDefaultProcessorCount" in the Developer Settings tab in Swarm. After the change to make Lightmass build asynchronously while the user keeps working, this set ...

Navmesh seems to have buggy behavior when interacting with HISMCs that programmatically set mesh via SetStaticMesh.

UE - AI - Mar 6, 2020

Both versions works correctly if HISMC is pre-placed (generated in ConstructionScript). Only when generated dynamically does it fails. The Navmesh isn't being updated after SetStaticMesh and AddInst ...

'Random Pitch Angle' not working when 'Collision with World' is enabled for Foliage instance settings

UE - World Creation - Worldbuilding Tools - Foliage - Jan 16, 2017

The 'Random Pitch Angle' setting within the Foliage instance settings are being overridden or ignored when 'Collision with World' is also enabled. This occurs in the binary releases of 4.12.5, 4.13 ...

Apex Cloth disappears when Setting Custom Time Dilation to Zero

UE - Simulation - Physics - Character - Aug 24, 2016

Apex Cloth assets disappear if you set the Custom Time Dilation to 0.0. You can workaround the issue by setting the Custom Time Dilation to 1.0, and then use the 'Force Cloth Next Update Teleport a ...

Adding a key frame to the curve editor in UMG adds multiple keyframes

UE - Editor - UI Systems - May 6, 2015

When Right clicking and selecting add key frame to an animation on the curve editor in UMG there appears to be multiple keys being added to the timeline. ...

Unable to delete levels with Particles in them

UE - Gameplay - Oct 9, 2019

The engine is unable to Level that has a Blueprint actor with a child actor component that has a particle system component. The follow message pops up: World /Game/LevelName.LevelName is in use. — ...