Crash when attempting to change the parent of a material instance constant through editor scripting

UE - Rendering Architecture - Materials - Apr 9, 2025

The built-in class "UMaterialEditingLibrary" provides various editor scripting functions related to creating and editing materials and material instances. One of these functions, UMaterialEditingLib ...

Source Control: Perforce Branch History is Parsed Incorrectly

Tools - Sep 26, 2016

Several issues have been reported within the ParseHistoryResults method from PerforceSourceControlOperations: 1. Any Records that share the same filename will only display the last record with that ...

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 ...