Blueprint editor can crash on removing one of a Sequence node's exec pins

UE - Gameplay - Blueprint Editor - Dec 22, 2023

User reported that upon removing a pin from a Sequence node the editor crashed. This only happened once, so may be a multithreading race condition or there may be additional unknown factors. The cra ...

Disabling Disregard for GC with an invalid asset in GameplayTagTableList causes a controlled crash

UE - CoreTech - UObject - Jul 31, 2024

Disabling Disregard for GC leads to a crash in GarbageCollectionVerification.cpp VerifyObjectFlags. This crash occurs when there is an invalid path specified in GameplayTagTableList. The cause of t ...

5.4, FRHIMemoryPool leaks memory

UE - Rendering Architecture - RHI - Feb 12, 2025

FRHIMemoryPool will leak data when it is destroyed. "FRHIMemoryPool::Init()" will create "FRHIMemoryPool::DesiredAllocationPoolSize" new "FRHIPoolAllocationData" objects, stored in "FRHIMemoryPool: ...

FX.TestGPUSort fails on Vulkan

UE - Niagara - May 5, 2025

“FX.TestGPUSort” fails on both PC Editor and Android with Vulkan RHI. ...

GetOverlappingComponents does not work on Mobile

UE - Simulation - Physics - Jun 13, 2016

The GetOverlappingComponents node isn't working correctly on mobile devices. It seems like it may only not be registering components that are spawned at runtime, as it does change the number of over ...

Negative Play rate in an Anim Sequence added to a Montage Causes timeline to collapse

OLD - Anim - Jan 14, 2015

Adding animations with a negative play rate (playing backwards) or modifying existing animations in a montage to have a negative play rate causes the timeline in the montage to "squish" and is no lo ...

Apex Cloth LOD distortion occurs after World Origin Rebase

UE - Simulation - Physics - Character - Sep 13, 2017

There is a distortion that occurs with Apex cloth when changing the World Origin location. This distortion occurs when you approach after the world origin has been changed. This issue is similar to ...

Arrays on multicast events called from the server are not passed to clients

UE - Networking - Jul 19, 2018

Arrays that are passed into a Multicast Event as an input are not available on clients who call the function Regression?: Yes This did not occur in 4.19.2 ...

Niagara Sub UV Index ignored

UE - Niagara - May 16, 2019

Using the Particles.SubImageIndex has no effect on what portions of the a UV are rendered in Niagara. Tested in 4.21.2 (CL - 4753647), 4.22.1 (CL - 6063286), 4.23 (CL - 6533064) ...

FCanvasTriangleRendererItem relies on BaseVertexIndex not being zero.

UE - Rendering Architecture - RHI - May 20, 2019

The root of this issue is that FLocalVertexFactory is doing manual vertex fetch in the shader. In HLSL, this relies on SV_VertexId. In GLSL, it's gl_VertexId. HLSL does not include the base vertex i ...