Certain combined Linear/Angular movements cause Client to freeze for several seconds

UE - Simulation - Physics - May 24, 2019

When using Replicated Movement, certain combined linear/angular movements cause the client to freeze for several seconds and then catch up to the server. This is a regression from 4.21.2 (CL-4753647 ...

Consolidate tool fails to replace unloaded references to Material Instances

Tools - Feb 20, 2018

This issue is not a regression, it has been broken since the start of UE4. This bug may be related to [Link Removed] . Per licensee: We are trying to replace certain materials with material instan ...

Skeletal Meshes have physics collisions lag

UE - Simulation - Physics - Oct 2, 2019

Skeletal mesh's physics collision lag behind the actual mesh. It didn't matter if there was just a root bone or multiple bones/constraints. This doesn't happen when using static meshes. The effect ...

Getting Fullscreen or Windowed Resolutions doesn't fully execute on Linux

UE - Rendering - Architecture - RHI - Oct 28, 2019

When using "Get Supported Fullscreen Resolutions" on UE when built with Vulkan, no values are printed out. This is an issue with any platform that builds UE with -vulkan, not just Linux.  In Engine ...

Interpolators of Particle Dynamic Parameters Need "nointerpolation".

UE - Niagara - Aug 1, 2019

Regardless Niagara or Cascade, dynamic parameters for particles are passed to pixel shaders from vertex shaders via InterpolantsVSToPS. It can cause a precision error on some materials, for example ...

Phaser module is malfunctioning

UE - Audio - Apr 9, 2019

The phaser module that is part of the new Audio Engine causes audio from a Sound Cue to mute after playing for one second. The user states that the issue comes from the Phaser.cpp file producing a N ...

[CrashReport] UE4Editor_Persona!<lambda_e529d88d0657fbede17be1535bc6d479>::operator() [blendspacedetails.cpp:29]

OLD - Anim - Aug 14, 2017

This is a trending crash coming out of the 4.17 release. Users have not provided any descriptions of their actions when the crash occurred. The callstack is very close to https://jira.it.epicgames ...

Desynchronised playback of firstime played SoundWaves with active AudioStreamCaching

UE - Audio - Mar 25, 2020

The SoundWave in the Content folder of the attached Project has been exported from Nuendo @ 120BPM 4/4, with a duration of exactly 1 Bar. The BP_Audio Actor uses the TimeSynthComponent to provide sa ...

Collision profiles are reset when blueprint is loaded

UE - Gameplay - Jan 6, 2025

In UE 5.5 (and earlier versions), FCollisionResponse::operator== has incorrect behavior where it will detect that two collision response containers are identical if they have the same number of entr ...

UText3DComponent's Text property access: UE 5.3 broke BP setters. UE 5.6 unneccessarily broke compatibility and incorrectly removed BP getters.

UE - Core - Systems - Jul 30, 2025

Class UText3DComponent from the "Text 3D" plugin contains a "FText Text" member which must be set through a SetText() function to correctly update the component's internal state. Up to UE 5.2, "Tex ...