Unreal Engine Issues
Unreal Engine Issues
Sub-world partitions do not properly handle partial editor loading as world partition standalone level instances' spatially loaded actors do not get loaded even when the Level Instance is force loaded or loaded in by region.
UE - World Creation - Worldbuilding Tools - World Partition - Aug 19, 2025Context Level Instancing is a level-based workflow designed to improve and streamline the level editing experience. In a standalone Level Behavior, when the Level Instance Actor is loaded through it ...
Player Character does not collide with landscape
UE - LD & Modeling - Terrain - Landscape - Mar 8, 2015UPDATE: 3/9/2015 Additional Information: User on thread https://answers.unrealengine.com/questions/186928/landscape-collison-issues-recreatelandscapecollisi.html reported workaround did not fix e ...
When using object lit by the Indirect Lighting Cache sometimes the cache will not load correctly for movable objects when a level is streamed that contains a landscape
UE - LD & Modeling - Terrain - Landscape - Jun 26, 2015When setting up a scene with a persistent level and any sublevel that contains a landscape that is loaded via load stream level node in the level BP can cause the ILC to not be correctly assigned fo ...
Crash after creating a suboject for RootComponent if the actor is placed on the level
UE - Foundation - Cpp Tools - Hot Reload - Nov 6, 2020The crash occurs when trying to assign a new value to RootComponent if the Pawn is already placed on the level Crash does not happen in P4 //UE4/Release-4.25.3 CL 13942748 Other steps to reproduc ...
Niagara Scalability Crash When Processing Significance
UE - Niagara - Jun 4, 2025Method FNiagaraScalabilityManager::ProcessSignificance() iterates on indices from Context.SignificanceIndices and uses them to access the State and ManagedComponents arrays. It can then decide to cr ...
Virtual Memory leak when using specific rendering settings in the template project
UE - Rendering - Architecture - RHI - Dec 20, 2025When a project is run with these settings in a template project, untracked virtual memory increases. Cvars r.GBufferFormat 3 r.Lumen.TraceMeshSDFs 1 r.Lumen.TranslucencyReflections.FrontLayer.Enab ...
DOF - TAA pass ghosting when using r.DOF.TAA.CoCBilateralFilterStrength
UE - Rendering - Graphics Features - Aug 7, 2025In Unreal 5.6, there's a new CVar: r.DOF.TAA.CoCBilateralFilterStrength, which should help with ghosting artifacts introduced by TAA in DOF passes. However, it doesn't work as expected since many gh ...
Crash Importing Skeletal Mesh LODs with a lot of morph targets
OLD - Anim - May 18, 2016Crash Importing Skeletal Mesh LODs with a lot of morph targets Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 785] Array index out of bounds: 2 from an ar ...
Crash related to Vertex Painting - MeshPaint!CastChecked<AActor,UObject>()
Tools - May 23, 2016This crash was reported on the UDN. Upon further investigation it has been experienced by a handful of different users throughout 4.11 and 4.12. JIRA logged for tracking despite unknown repro steps ...
Lumen Global Distance Field Trace Leaking due to Surface Cache Sampling
UE - Rendering - Graphics Features - Jan 12, 2026At specific distances from a thin wall, surfaces inside of a sealed chamber can receive indirect lighting from outside, leaking light into the chamber. This appears to be due to how SWRT handles sa ...