Copy-pasting (in the details panel) an array of structs containing multiline text not coming back entirely correctly

UE - Editor - UI Systems - Slate - Dec 20, 2016

This is the copy buffer (it contains multiline strings): ((SectionName_10_AD815C6B40E1AA91C8FB72B006CB648A="TeamScreen_Overview",TipHeader_8_0A891281438C7AD03199038A729ACC18="Heroes",TipBody_9_C20B ...

UnkownRef Mips can cause TextureStreaming peaks during loading

UE - Rendering - Graphics Features - Mar 27, 2023

UnkownRef Mips is meant to fix/workaround the problem where some textures are used for rendering but they don't have any component references them (such as texture used by PP effects) These UnkownR ...

Material attribute layers issue with texture sample and VT lookups

UE - Rendering - Architecture - Materials - Nov 14, 2024

When using material attribute layers in a material layer setup, there is a potential discrepancy in the number of VT Lookups presented in the material instance's Platform Stats. When the same textur ...

[bug] OIT doesn't work correctly with alpha composite blend mode

UE - Rendering - Features - Shading Models - Mar 4, 2025

When using OIT, AlphaComposite Materials blend as if they are using the Translucent BlendMode. The order of macro #if … #elif cases cause AlphaComposite Materials to take the same route as Transluce ...

Open Formats: Interchange Import PIE - Importing static mesh while a PIE session is running permanently breaks nanite on the asset

UE - Editor - Open File Formats - Mar 12, 2025

Importing a Static Mesh during PIE can cause it to never enable Nanite, even if it reports that Nanite is enabled. To re-enable Nanite on the mesh, the asset needs to be deleted and imported again ...

Blackboard decorator node does not abort lower-priority nodes

UE - AI - Feb 16, 2026

When a branch of a selector is deactivated, all auxiliary nodes and observer delegates are removed. If the branch is reactivated soon and the CurrentActiveNode remains unchanged, the behavior tree l ...

Cannot Increment a Blackboard Key Value

UE - Gameplay - Blueprint - Feb 4, 2016

Getting a blackboard value as int and then attempting to increment it does not actually increment the value. Upon attempting to increment a value that started at 0, the editor continued to print out ...

[CrashReport] Commandlet crash - UE4Editor_Engine!FAnimationUtils::CompressAnimSequenceExplicit() [animationutils.cpp:621]

OLD - Anim - Sep 7, 2017

This is an infrequent commandlet crash that has affected a number of users exclusively in 4.17.1 (possible regression from 4.17.0?). There are also two instances of older cases in 4.13 and 4.15, bu ...

Mutable: Child parameters hidden when intermediate Object Group uses "All Options"

UE - Anim - Mutable - Mar 31, 2026

FCustomizableInstanceDetails::FillChildrenMap() unconditionally registers parent-child relationships via __ParentParamName metadata without verifying the parent exists in the active parameter list. ...

Overlapping isn't updated on replicated components after SetWorldTransform

UE - Networking - Dec 10, 2015

Overlapping isn't updated on replicated components after SetWorldTransform. Updating the transform on the Actor itself updates the overlapping as expected. Reproduced in 4.10 and Main (CL# 2798114) ...