Unfocused Standalone window has reduced performance

UE - Rendering Architecture - RHI - Aug 25, 2020

User description: When I run two windowed standalone instances to test multiplayer, the unfocused window gets about 2-5 fps...but if I focus on it, smooth 120fps, yet the opposite screen is now onl ...

Crash when quick binding a function in a class that extends LevelSequenceDirector

UE - Anim - Sequencer - Sep 16, 2020

The purpose was to create a Level Sequence Director inheritance class so that the same event could be reused in multiple sequencers. Attempting to quick-bind this base Level Sequence Director event ...

[CrashReport] UE4Editor_CoreUObject!FLinkerSave::FLinkerSave() [linkersave.cpp:31]

UE - Foundation - Core - Aug 22, 2017

This is a longstanding and common crash that has occurred since at least the 4.11 release. The error appears to occur while trying to access a .tmp file. User DescriptionsI left unreal unattended ...

Race condition in full builds of UE4 engine source

UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 26, 2019

This is a race condition caused by how "Clean.bat", a batch file used during rebuilds, tries to manually rebuild the UnrealBuildTool project when it runs. This causes a spam of UnrealBuildTool build ...

[CrashReport] UEdGraphSchema_K2::PinHasSplittableStructType

UE - Gameplay - Blueprint - Sep 14, 2017

This crash is affecting a few users in 4.17. ...

Niagara Emitter editor forgets Timeline playback ranges

UE - Niagara - Sep 14, 2020

This seems to only affect an emitter and not a system asset. ...

PlayerController::PlayDynamicForceFeedback called through code does not fire

UE - Gameplay - Input - Feb 25, 2016

Calling PlayDynamicForceFeedback in code does not affect controller rumble. ...

Physics Thruster has no effect on destruction mesh

UE - Simulation - Physics - Destruction - Apr 13, 2015

Physics Thruster actor does not affect destruction meshes that it is attached to. ...

Ray traced shadows appear even after the mesh is hidden

UE - Graphics Features - Lumen - Oct 13, 2020

bCastHiddenShadow flag in UPrimitiveComponent doesn't affect ray tracing shadows ...

Landscape GrassType does not have the option to exclude Decals

UE - World Creation - Worldbuilding Tools - Foliage - Feb 8, 2016

Landscape grass type lacks the option to disable decals from affecting it. ...