Unreal Engine Issues
Unreal Engine Issues
Material Slot Names Get Replaced With "None" After Merge Actors Operation
Tools - Mar 23, 2017After 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, 2019The 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, 2019Root 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 ...
[Sound Cue][Open World] - Crash when creating a Sound cue from an Ambient Sound actor on an Open World map
UE - World Creation - Worldbuilding Tools - OFPA - Apr 18, 2022When trying to recreate an issue that resulted in [Link Removed], I came across this call stack. Regression testing done in //UE4/Release-4.27.2 CL-18427296 and this issue did NOT happen. ...
Crash when recombining Value Pin after swapping Target Wild Card pin from a Vector2D to a Vector on a Set By-Ref Var node
UE - Gameplay - Blueprint - Jul 18, 2022This is not a regression. Tested in //UE4/Release-4.27 CL18319896 Crash when recombining Value Pin after swapping Target Wild Card pin from a Vector2D to a Vector on a Set By-Ref Var node. ...
ISM Component in an instanced BP does not take into account changes to NumCustomDataFloats from the BP class
UE - Graphics Features - Sep 16, 2022PerInstanceSMCustomData 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, 2023The 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, 2024When 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 ...
Point light leaking throught thin geometry
UE - Graphics Features - Oct 29, 2024In 4.27, ray traced point lights can leak through thin meshes. This bug does not exist in Unreal Engine 5, due to many of the potential rendering areas being fundamentally changed. ...
Performance hitch from RemoveGeometryCache flushing the render thread
UE - Editor - Content Pipeline - Alembic - Jun 12, 2025FGeometryCacheStreamingManager::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 ...