Unreal Engine Issues
Unreal Engine Issues
OnActive Gameplay Cues not activating properly in standalone
UE - Gameplay - Nov 28, 2016This was reported from https://udn.unrealengine.com/questions/323255/bugfix-onactive-not-triggering-for-gameplaycues-on.html In some case it looks like OnActive gameplay cues are not working proper ...
Editor crash on level load when bUseActorFolders is true after dragging Actor into another folder in the Outliner
UE - World Creation - Worldbuilding Tools - OFPA - Mar 7, 2023From licensee: Hello! Our level streaming setup enables the bUseActorFolders on our levels. When moving the Actor into another folder via the Outline, the editor will crash on the next load Assert ...
Physics Constraints have unexpected behavior when used on nested static mesh components
UE - Simulation - Physics - Jul 5, 2017Physics Constraints have unexpected behavior when used on nested static mesh components. Simulating inside of the blueprint has a similar effect to what is expected but when the BP is added to the l ...
Interpolators of Particle Dynamic Parameters Need "nointerpolation".
UE - Niagara - Aug 1, 2019Regardless Niagara or Cascade, dynamic parameters for particles are passed to pixel shaders from vertex shaders via InterpolantsVSToPS. It can cause a precision error on some materials, for example ...
RVT output from Landscape Height gets incorrect mip cache loaded
UE - Graphics Features - Oct 13, 2021I test it for more information for your reference:It happens only when a Landscape *Height *was output to the RVT, other Landscape's maps like BaseColor are all fine, as well as Height output from o ...
Light as If Static setting does not Persist when Re-opening Project
Tools - Apr 28, 2016This bug was originally entered back in 4.8 as [Link Removed], but was closed as by design. The reason was, the mesh did not have Lightmap UVs, so using the 'Light as If Static' option would not wor ...
HLODs appear dark/near black when built for very large geometry with Virtual Textures enabled
UE - World Creation - Worldbuilding Tools - HLOD - Jan 27, 2025Building HLODs for a very large landscape with Virtual Textures enabled results in the built HLODs being very dark for the most part. Building the same large landscape's HLODs with Virtual Textures ...
Missing PSO Precaches in the engine
UE - Rendering Architecture - RHI - Aug 20, 2025A licensee wanted to report some missing PSO Precaching they found, which they have fixed locally: 1. UCableComponent doesn't implement CollectPSOPrecacheData or call CheckPSOPrecachingAndBoostPri ...
Crash When Loading Cooked Material Assets in Editor Due to Shader Serialization
UE - Rendering Architecture - Shaders - Aug 27, 2025In Unreal Engine 5.6+, the new shader serialization logic in FShaderMapResourceCode::Serialize does not correctly handle cooked assets that are loaded back into the editor (e.g., from a mounted .pak ...
Cooker is asserting in Class.h on UE 5.7.1
UE - CoreTech - Dec 18, 2025From the linked EPS case: ---------------------------- In UE 5.7 there were some changes to how Enum member names are stored. This change introduces an assert when cooking using the Editor Debug e ...