GPU Particle Collision causes shaking when set to bounce with low resilience.

UE - Niagara - Jul 27, 2016

A particle emitter with GPU sprites on certain settings will shake violently as they collide with the ground. This requires there to be a strong Const Acceleration module and Collision with low resi ...

Set Skeletal Mesh does not replicate or multicast to Clients

UE - Networking - Jul 5, 2019

The Set Skeletal Mesh function does not replicate or multicast to other Clients. In Setup A (Level Blueprint) only the Sever Character is changed on either the Client or Server. In Setup B (ThirdPer ...

PIE with Auto Recompile Blueprints disabled generates an error message asking to compile PROTO_BP Blueprints

UE - Gameplay - Blueprint - Mar 17, 2015

PIE with Auto Recompile Blueprints disabled generates an error message asking to compile PROTO_BP_Blueprint_0 and PROTO_BP_AnimBlueprint_0. Clicking Yes compiles, but any attempt to PIE thereafter g ...

GetKnownPerceivedActors doesn't stop calling when specified AISense should be forgotten

UE - AI - Mar 17, 2019

There is a difference in implementation and set of checks that are made in GetKnownPerceivedActors() depending on if you use specific SenseClass or leave it as nullptr (so it will return info for al ...

Suspend/resume iOS Metal Crash on low end device with MTLCommandBufferErrorMemoryless error with lots of geometry

UE - Platform - Mobile - May 11, 2023

The project was built in Unreal 4.27.2 binary from the Epic Games Launcher. At this stage we have only observed the crash on devices with a hardware combination of Apple A9 1.8 GHz and 2GB of Memory ...

Anim Graph will hang if the Draw Debug Sphere and Set node are connected and compiled

UE - Anim - Runtime - Anim Blueprints - Jun 8, 2023

anim blueprint hangs when compiled. Probably a cyclic issue when compiling. A workaround is to add a delay of any time between the set node and the Draw Debug Sphere node. Repros in the following v ...

Auto Reimport crash with some file paths

UE - Editor - Content Pipeline - Import and Export - Dec 14, 2016

Auto Reimport source paths can cause a crash with the editor. I couldn't narrow down in my limited testing what would cause the crash vs what would not with these file paths. The one in my attached ...

Modulated Shadows on IOS cause flickering on Skeletal Meshes

UE - Platform - Mobile - Feb 10, 2016

Modulated shadows are not functioning properly on IOS devices for skeletal meshes. Any skeletal meshes in the scene will cast a shadow, but have a flickering modulated shadow on the skeletal mesh as ...

Crash on Device when Deploying Mobile Project with Modulated Shadows and Planar Reflections on iOS 9

UE - Platform - Mobile - Jan 6, 2017

A crash occurs on iOS when deploying the licensee's project using iOS 9 version. The crash does not occur when deployed to a device using iOS 10 version. They believe the crash to be related to Pl ...

Foliage Instanced Static Meshes disappear when FISM Component BP is compiled

UE - World Creation - Worldbuilding Tools - Foliage - Nov 10, 2017

This bug removes foliage from a level when the Component Blueprint is compiled. Switching the Foliage type asset to another component will cause the issue to stop occurring. The Component Blueprint ...