Invalid GUIDs on new material instance parameters cause overrides to break on base param rename

UE - Rendering - Architecture - Materials - Sep 3, 2025

When a parameter value is assigned on a newly created material instance (constant or dynamic) using Set***ParameterValueInternal, the parameter’s ExpressionGUID is left invalid (0,0,0,0). Parameter ...

Landscape Components No Longer Editable after Undoing Component Deletion

UE - LD & Modeling - Terrain - Landscape - Oct 20, 2015

When working in Manage Mode with Landscapes and deleting a component, if you undo the deletion, you can no longer modify or select the component. I did attempt to rebuild the scenes lighting and ge ...

High Res Screenshot Tool Scene Color rendering washed out as EXR

UE - Graphics Features - Dec 8, 2015

When rendering out the Buffer Visualization Targets with the HDR setting on, the resulting Scene Color EXR is rendering significantly washed out compared to the Buffer Viz. in the Editor and if comp ...

Typo in "BaseEditorSettings.ini": under section [/Script/UnrealEd.ContentBrowserSettings], key "DisplayPluginFolder" (singular) should read "DisplayPluginFolders" (plural).

UE - Editor - Oct 11, 2025

File "<ENGINE_PATH>/Engine/Config/BaseEditorSettings.ini" contains the following setting: [/Script/UnrealEd.ContentBrowserSettings] ; Whether to display the game project plugins in the Content Brow ...

Behavior of configuration file hierarchy is different from document

UE - Foundation - Core - Nov 6, 2015

Licensee reported behavior of configuration file hierarchy is different form document here (https://docs.unrealengine.com/latest/INT/Programming/Basics/ConfigurationFiles/index.html) Doc: 1. Engine ...

Python crash the engine at exit.

UE - Editor - Oct 25, 2022

A UDN reported various crashes at exit in the embedded Python library. I was able to repro the issue in Release-5.1 and trace it back at the point where python runs its garbage collection in Py_Fina ...

Physics Substepping doesn't have the same effect from 4.15 to 4.16

OLD - Anim - Aug 8, 2017

Physics Substepping doesn't have the same effect from 4.15 to 4.16. In 4.16+ the ponytail in the provided project will have a jitter effect even with substepping enabled. This is a regression: Work ...

Collision profiles are reset when blueprint is loaded

UE - Gameplay - Jan 6, 2025

In UE 5.5 (and earlier versions), FCollisionResponse::operator== has incorrect behavior where it will detect that two collision response containers are identical if they have the same number of entr ...

[CrashReport] Mac crash - UE4Editor-Slate.dylib!FTextLayout::GetAsTextAndOffsets()

UE - Platform - Apple - Aug 15, 2017

This is a trending Mac crash in 4.17.0 that also had some occurrence in 4.16. Users have not provided any descriptions of their actions when the crash occurred, but the callstack is nearly identica ...

iOS Metal-based build crashes at launch with sub-levels.

Tools - May 16, 2016

Application crashes when deploying a game to iOS with Metal enabled. This has only been reproduced if a sub-level has been added to the starting level within the project. This seems to only happen ...