Bug in StringTemplate.cpp related to modulo operator in MaterialTemplate.ush (code fix provided)

UE - Rendering - Architecture - Materials - Jun 25, 2024

Shader Template files like MaterialTemplate.ush do not submit previous chunks when encountering a `%` character, unless that `%` character is `%s` or `% {...} `. Because the error is happening ...

Updates to DesiredFocusWidget for a UserWidget are not propagated to existing instances of it inside the WidgetTree of other widgets

UE - AI Workflows - UI Systems - Nov 17, 2025

This issue has been reproduced in UE 5.3 to 5.7 and source versions. A repro project is available. Below are the findings from an initial investigation of the problem. Normally, when a UserWidget p ...

[CrashReport] UE4Editor_Engine!FViewMatrices::FViewMatrices()

UE - Graphics Features - Aug 3, 2017

This is a trending crash in the 4.17 previews. Unfortunately users have not provided any descriptions of their actions when the crash occurred. Source Context 464 FViewMatrices::FViewMatric ...

Fix up IOS errors calling UI API from non-UI threads

UE - Platform - Apple - Jul 27, 2020

Packaging with plugins GearVR and GoogleVR together cause build failed with multiple definitions of GetHMD()

UE - Platform - XR - Sep 7, 2016

Packaging with plugins GearVR and GoogleVR together cause build failed with multiple definitions of GetHMD(). Log attached for build error and error portion plugged into the callstack box. ...

DLC Package content isn't recognized when using RequestAsyncLoad

UE - Foundation - Core - May 24, 2016

Attempting to load dlc assets with RequestAsyncLoad function results in the assets not being recognized. ...

Unable to change Actor Coloration View Modes in PIE

UE - World Creation - Worldbuilding Tools - Jul 20, 2025

When in PIE changing Actor Coloration view modes from the viewport visualisation mode [Liit] -> [Actor Coloration] -> ... Does not update correctly when switching view mode and sometimes isn't corr ...

FileSystemDerivedDataBackend may output a corrupted access log

UE - Foundation - Core - Derived Data - May 20, 2021

This problem is caused by the AccessLogWriter has not been flushed at the termination. The following workaround flushes the Writer.class FFileSystemDerivedDataBackend : public FDerivedDataBackendInt ...

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

UE - Runtime - Character - Nov 12, 2025

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

Crash after importing a 16k Normal Map while Unreal Real is Preparing Texture

UE - Texture - Sep 12, 2022

This is a regression tested in //UE4/Release-4.27 cl18319896 Editor crashes after importing a 16k Normal Map while Unreal Real is Preparing Texture. Other non-normal maps seem to work without issue ...