Certain UPROPERTY values are not updated during auto-recompile

UE - Gameplay - Blueprint - Aug 4, 2016

Sometimes manual recompile is required to make a blueprint actually recompile data-only changes, but not always. If the last manual compile was with default values, then changes are not updated. If ...

Adding pin to CR node causes crash if input variable is assigned to one of the array element

UE - Anim - Rigging - Control Rig - Aug 22, 2025

When a node has a variable assigned to one of its pins. You will get a crash every time you add a pin. I am sure this goes for all nodes with with the "add pin" functionality [Link Removed] ...

A Simulating Physics component with StartAwake = false will be awoken by a Welded component

UE - Simulation - Physics - Jan 10, 2025

A Simulating Physics component with StartAwake = false will be awoken by a Welded component If a welding occurs during the call to OnCreatePhysicsState, this breaks the start awake disabled flag. Th ...

Deploying from Windows to Linux fails on the first attempt

UE - Platform - Linux - Aug 3, 2017

After hitting this failure, if you try to deploy again, then it will work. This only occurs on the first attempt. Initially, I thought I hit a disc space issue I was hitting due to having a sample ...

Actor ClassID Value Read From Data Table only in PIE

UE - Gameplay - Blueprint - Sep 22, 2016

When accessing a data table in BP and getting an Actor Class from it the Class will return NULL when in Standalone Game, Launching, or in a packaged game. This only seems to work in PIE. ...

Draw as border is completely opaque when size in negative

UE - Editor - UI Systems - Feb 26, 2019

When an image widget is set to draw as border it will no longer render as a border if the size is negative. The widget appears completely opaque. ...

GetAllMobileRelevantLayerNames drops those layers which are only connected to RuntimeVirtualTextureOutput Node

UE - Graphics Features - May 6, 2021

in UMaterial::GetAllReferencedExpressions, the mobile branch ignores every CustomOutputExpressions including RuntimeVirtualTextureOutput. ...

Ensure after reparenting Blueprint and moving a property to the new parent

UE - Gameplay - Blueprint Editor - Jul 20, 2023

Moving a property from a recently reparented BP to its new parent will assert in  FBlueprintCompileReinstancer::MoveDependentSkelToReinst at  ensure(PrevStructSize == NewStructSize) This only see ...

FBX import freezes in DataPrep

UE - Editor - Content Pipeline - Visual Dataprep - Mar 3, 2025

FBX file import freezes UE while trying to import into DataPrep by the Interchange importer. The import will start, but then a message will pop up stating "Creating snapshot of world content ... " ...