Importing specific Alembic geometry cache fails

UE - Editor - Content Pipeline - Import and Export - Oct 3, 2018

According to Licensee this problem seems to be caused by the time to sample the data. By changing the time to frame number, the import seems to be successful. \Engine\Plugins\Experimental\AlembicI ...

Update Mesh Section incorrectly sets vertex colors for a Procedural Mesh

UE - Graphics Tools - Modeling Tools - Jun 21, 2022

This is a regression tested in //UE4/Release-4.27 CL#18319896 Update Mesh Section incorrectly sets vertex colors for a Procedural Mesh. The closer a colors R, G, or B value is to 1.0 or 0.0 the mor ...

Crash when destroying a pawn on the client

UE - Networking - Jul 6, 2015

Crash when destroying a pawn on the client. Reproduced in 4.8.1 and Main (//depot/UE4/Promotable-CL-2610743). This is a regression: the crash does not occur in 4.7.6 Crash Report: [Link Removed] ...

Vector VM - Crash / memory stomp when using > 255 external function calls

UE - Niagara - Aug 12, 2025

The Vector VM has only every supported a byte's worth of external function calls, when we blew the limit it would index into the incorrect VM call. The new VM will also overwrite memory when exceed ...

Vulkan with Forward Shading & MSAA Crashes

UE - Graphics Features - Dec 23, 2019

Projects crash when the following Project Settings are set: • Vulkan is enabled • Vulkan is the Default RHI • Forward Shading is enabled • AntiAliasing Method is set to MSAA The different engine ve ...

Editor crashes on blueprint open when shortcut key is implemented through code

UE - Gameplay - Jun 7, 2017

Editor crashes on blueprint open when shortcut key is implemented through code inside of the BaseEditorPerProjectUserSettings.ini. Code used in repro is directly from Jeff W suggestion in the forum ...

Landscape Grasstype warning causes log spam when landscape is streamed in or out

UE - LD & Modeling - Terrain - Landscape - Nov 16, 2016

Using the Landscape Grasstype will generate log spam for the number of Landscape components being used or if using World Composition will generate a log warning for each tile used. The warning ind ...

Crash after creating a suboject for RootComponent if the actor is placed on the level

UE - Foundation - Cpp Tools - Hot Reload - Nov 6, 2020

The crash occurs when trying to assign a new value to RootComponent if the Pawn is already placed on the level Crash does not happen in  P4 //UE4/Release-4.25.3 CL 13942748 Other steps to reproduc ...

LayeredBlendPerBone without BlendRootMotionBasedOnRootBone exaggerates root motion

UE - Anim - Runtime - May 27, 2023

When BlendRootMotionBasedOnRootBone is false, the LayeredBlendPerBone is aggregating root motion of the child poses ontop of the base pose root motion.  (ie. if the first child pose's blend weight i ...

Failed to generate Nanite data for mesh with bDoFastBuild enabled

UE - Graphics Features - Nanite - Oct 1, 2025

If "bDoFastBuild" is enabled on a Static Mesh asset, in-editor it will never be able to have Nanite data built for it, preventing the Static Mesh from using Nanite. There is no way to fix this issu ...