Mover Plugin: UNavMoverComponent::GetFeetLocationBased() returns incorrect FBasedPosition when using WalkingMode over a Movable floor, making UPathFollowingComponent erroneously detect a blocked move

UE - Gameplay - Player Movement - Mover - Nov 12, 2025

Function UNavMoverComponent::GetFeetLocationBased() on file "NavMoverComponent.cpp" returns an FBasedPosition built from an FRelativeBaseInfo. The "MovementBaseInfo" is read from key "CommonBlackboa ...

Detour AI Controller Not Functioning Properly

UE - AI - Oct 30, 2015

Using AI Detour in 4.9.2 works as expected, however, when upgrading a project from 4.9.2 to a newer version, the AI pawns fail to properly navigate around each other when moving to their respective ...

Force front x imported asset incorrectly display axis for thumbnail and default editor camera

UE - Editor - Content Pipeline - Import and Export - Apr 12, 2021

Thumbnail can be fix by (Quote from UDN) "adjusting OrbitYaw of the ThumbnailInfo for the +X-facing skeletal mesh" Persona Editors can be fix by (Quote from UDN) "setting SkeletalMesh->SetHasCustom ...

Changing the case of any node with a String input will not be saved

UE - Gameplay - Blueprint - Apr 20, 2016

Changing the case of any node with a String input will not be saved User Description: Changing case of any string input in BP not accepted But the problem is still happened on any string input of ...

Editor will crash on attempt to load a previously-saved Blueprint asset with a serialized default subobject containing a serialized static array of two or more nested subobject instances.

A crash will result if a Blueprint class that's based on a native C++ class containing two or more nested, explicitly-instanced subobjects referenced by a fixed-size object array property are serial ...

Blendspace Animation Lag for Morph Targets

OLD - Anim - Sep 11, 2015

Blendspace animations of morph targets play at a slightly but noticably different rate between the 4.8 and 4.9 version of the UE4. ...

Crash when ribbons use delayed spawn particle as source.

UE - Graphics Features - Dec 3, 2015

User has found bug but has a working fix. Verify fix and implement in engine. ...

WASM HTML5 Runs out of Memory in Chrome versions 58+ on Windows

UE - Platform - Mobile - May 5, 2017

We were seeing out-of-memory errors when launching on Chrome version 58 on Windows (both 32-bit and 64-bit). After some investigation, the root cause appears to be a regression introduced in Chrome ...

Set world or relative rotation on a child component sets the wrong rotation

UE - Gameplay - Blueprint - Aug 21, 2018

Unexpected results from setting relative rotation on child of child in BP. Also confirmed in Main CL 4302610 "I have found that changing this code from RelativeRotationCache . RotatorToQuat (NewRe ...

Moving assets in the Editor fails to fixup references causing the project to generate errors

Tools - Mar 30, 2020

Moving assets in the Editor is very unreliable. References may or may not be fixed up. No direct error is presented or a warning about problems. Any moves of the gameinstance, string table or certai ...