Collision Meshes Are Ignored Until FBX Is Reimported

Tools - Feb 20, 2017

When importing a mesh with it's collision geometry and its LOD meshes all contained within the same group it won't import the collision geometry correctly. This can be fixed by simply right clicking ...

Material Slot Names Get Replaced With "None" After Merge Actors Operation

Tools - Mar 23, 2017

After merging two actors the resulting merged actor's slot names will be replaced with "none". Fixing this is a very tedious process for our licensee since there usually is a large amount of slot ...

Private lobbies cannot be invited to on Steam

UE - Online - May 13, 2019

The old method doesn't work with private match invites as it doesn't have the right security permissions. It's still valid for dedicated servers. It also doesn't work properly with lobbies on VR eit ...

Montage Root Motion does not work from sub anim instances

UE - Anim - Gameplay - Oct 25, 2019

Root motion from sub instances is not used when the parent instance is marked as 'Root Motion from Montages Only'. Proposed fix is to modify USkeletalMeshComponent::IsPlayingNetworkedRootMotionMo ...

ISM Component in an instanced BP does not take into account changes to NumCustomDataFloats from the BP class

UE - Graphics Features - Sep 16, 2022

PerInstanceSMCustomData is bulk serialized and doesn't get changed on the BP instance when changing NumCustomDataFloats, possibly causing out of bounds array access leading to a crash. Possible sol ...

FMaterialResource::IsDualBlendingEnabled bug

UE - Rendering Architecture - Materials - Jul 24, 2023

The user has a proposed fix for this in the case. FMaterialResource::IsDualBlendingEnabled needs the following modification that includes MaterialInstance check: bool bMaterialRequestsDualSourceBle ...

Auto Exposure Compensation Curve issue when switching from Histogram to Manual

UE - Rendering Architecture - Feb 21, 2024

When switching the Camera's Exposure Metering Mode from Histogram to Manual, there is a single-frame flash. The Licensee has a proposed code change that would fix this issue. Also found in 5.4, CL 3 ...

Performance hitch from RemoveGeometryCache flushing the render thread

UE - Editor - Content Pipeline - Alembic - Jun 12, 2025

FGeometryCacheStreamingManager::RemoveGeometryCache calls FlushRenderingCommands which shows up as a hitch when profiling. [Link Removed] Ideally the flush added in CL#23782411 to fix a rare deadl ...

Ensure starting PIE after editing character blueprint of a code based side scrollers

UE - Gameplay - Apr 6, 2016

After editing character blueprint of a code based side scroller project, starting PIE will show the camera detached from the character and exiting PIE causes the project to crash. NOTE: This appear ...

Crash Occurs When Renaming Folder in Landscape Mountains Project

Tools - Jun 23, 2016

Changing the name of a newly-created folder that contains a few copies of the same map causes a crash in the Landscape Mountains project. This crash did not occur in a clean First Person project wh ...