Single sided complex collision mesh collision blocks character movement from backside

UE - Simulation - Physics - Query - Nov 17, 2023

Commenting out the branch in FTriangleMeshSweepVisitor::VisitSweep is a work-around.if (CullsBackFaceSweepsCode != 0) { if (VectorMaskBits(IsBackFace)) { // Don't cull the back face ...

Conditional crash when a DragAndDrop operation is done betweeen Data Layers.

UE - World Creation - Worldbuilding Tools - Data Layers - May 8, 2024

A crash occurs to the engine as when we when have unreal as a backgroud task, and we try to drag and drop a layer to another by selecting the layer visibility button. ...

delete_all_material_expressions_in_function Doesn't delete all expressions in one go.

UE - Rendering Architecture - Materials - May 24, 2024

UDN: https://udn.unrealengine.com/s/case/500QP000009NxNBYA0/deleteallmaterialexpressionsinfunction-doesnt-delete-all-expressions-in-one-go?fromCase=1 A UDN user is reporting that the delete_all_mat ...

FILTER_COMMANDLINE_LOGGING cannot be used without forcing UE_COMMAND_LINE_USES_ALLOW_LIST

UE - CoreTech - Jul 30, 2024

There's two ways to affect the commandline in CommandLine.cpp: FILTER_COMMANDLINE_LOGGING - for filtering certain or all args (if left empty) from the log. UE_COMMAND_LINE_USES_ALLOW_LIST - for on ...

Frustum culling provides inconsistent results causing particles to render even when the bounds are out of view.

UE - Niagara - Rendering - Nov 5, 2024

When the camera is just outside of the box bounds and it is angled directly away from it , it will start rendering the particles again (as determined by stat GPU differences) despite being out of vi ...

Data loss with subobjects in Blueprint arrays

UE - Framework - Blueprint - Mar 6, 2025

Datasmith Direct Link models relocate on sync

TM - Interoperability - Jun 3, 2024

Reported by multiple users. Models imported through Datasmith Direct Link can be relocated after a sync, despite no edits to the geometry's location in the DCC program. Currently reported for both ...

If a file has been opened in the editor, it cannot then be unshelved by perforce until the editor is restarted

UE - Editor - Workflow Systems - Jul 8, 2022

When the Editor launches it does not have a file lock on assets that are not open. When the asset is opened for editing, UE gets a lock on the file and this lock persists even after the tab is close ...

IsLocalController returning incorrect value when PIE listen server travels back to standalone map

UE - Networking - Jun 11, 2025

In this situation where the listen server travels back to a level without listening, IsLocalController can return the incorrect value. After the NetDriver has been shutdown and destroyed, the pawn a ...

Crash importing morph targets with animation and opening it in animation editor

UE - Graphics Features - Mar 31, 2017

Lina encountered a crash when importing the attached FBX file with morph targets and animation, and then opening it in the animation editor. I was not able to reproduce this issue in QAGame (her re ...