Confusing build error message provided when semi-colon is not added after a forward declaration in an Interface header file

UE - Foundation - Cpp Tools - UnrealHeaderTool - Feb 15, 2019

If a forward declaration of a class is made in the header file for an Interface class, and no semi-colon is included at the end of the forward declaration line, the build will fail with a confusing ...

Creating Online Session always fails in Launch mode when loading another map

UE - Networking - Aug 5, 2019

Creating an Online Session and transitioning to another map does not work in a Launched Windows game. The transition event does fire but it just resets the players position on the Default map. This ...

Sequencer Media Tracks trigger crash when an ImageSource is added

Media Framework - Jun 18, 2020

The same callstack appears in 4.24.3 (CL-11590370) but only when playing a Sequence with a Media Track that has a ImgMediaSource and Media Texture set on it. These repro steps work for 4.25 and 4.26 ...

VFInitRotation(Cascade) always provides the same rotation

UE - Niagara - Jun 30, 2020

This problem caused by incorrect initialization of RandomStream in the GPU particle. //PaticleGpuSimulation.cpp virtual void Init() override { ... check(AllocatedTiles.Num() == TileTimeOfDe ...

BuildPatchTool doesn't finish if enabled building Http Chunk on Mac

Portal - Jan 25, 2021

We may fix this issue by the following codes. FPakPlatformFile::FPakPlatformFile(): LowerLevel(NULL) ,bSigned(false) { // remove //FCoreDelegates::GetRegisterEncryptionKeyMulticas ...

Nvidia Graphics Drivers cause editor menus to flicker and disappear after using the editor for an extended period of time

UE - Graphics Features - Apr 16, 2021

This issue seems to be occurring on a variety of Nvidia cards. So far, I haven't seen any indication that it is affecting AMD graphics cards. The majority of the reports have indicating that the pro ...

Enhanced Input Axis Actions repeatedly firing the last input value when entering a Common UI menu

UE - Gameplay - Input - Sep 7, 2023

When using an axis mapped input action such as looking around with a gamepad joystick, then opening a Common UI menu, the last input axis value will keep firing irrespective of the current joystick ...

Some instances spawned by NeagaraDataInterfaceChaosDestruction breaking event will be set location to the world origin

UE - Niagara - Data Interface - Nov 29, 2024

 The following code can often be found in UNiagaraDataInterfaceChaosDestruction.const int32 ParticleID = ParticleIDParam.GetAndAdvance() - LastSpawnedPointID + 1; The LastSpawnedPointID is usual ...

Editor 'Build All Levels' discards Volumetrics Lightmaps in persistent level

UE - Graphics Features - May 14, 2025

Building the level or lightmaps can clear the volumetric lightmap. In 5.5, this requires you to perform a full build, or a lighting only build with a BSP brush in the scene. In 5.6, all level build ...

Stationary Lights are causing shadowing errors with Movable Objects

UE - Graphics Features - Feb 11, 2015

Stationary Lights are generating shadows with flickering black square and vanish shadows altogether on movable objects in the Preview of 4.7p6 and in the newest Release Branch of 4.7 (2439472). The ...