Unreal Engine Issues
Unreal Engine Issues
HZB Occlusion causes large stalls on the render thread
UE - Rendering Architecture - RHI - Oct 7, 2025HZB Occlusion causes large stalls (greater than 5ms seen) on the render thread due to an RHI flush. This is caused by the following code in FDynamicRHI::RHIMapStagingSurface_RenderThread which force ...
Installed builds of the Engine cannot package game targets with optional game features
UE - Foundation - Build - Rocket (Installed Engine) - Mar 10, 2022The build system supports many types of flags that can be enabled in game-specific Target.cs files to enable things like logging in shipping, target-specific overrides like custom config, or enablin ...
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 ...
Custom Depth range is different than Pixel Depth range
UE - Graphics Features - Sep 25, 2025Shaders that compare custom depth and pixel depth get wrong output values because the ranges are different. This error is most noticeable over large distances. The difference in ranges is due to t ...
The pak file specified in PakFileRules is not created correctly
UE - CoreTech - Aug 8, 2023The rules by which chunks are created are ambiguous and currently do not ensure that both PakFileRules and PrimaryAssetLabel settings are reflected. In this sample, depending on the PrimaryAssetLabe ...
Incorrect behavior after attaching an actor to a non-root component of another actor in the Editor
UE - Editor - Workflow Systems - Jul 3, 2024UE allows actors to be attached to other actors. More precisely, it allows the root component of an actor (child) to be attached to any component of another actor (parent). From now on, "parent" and ...
Body Setup of a Static Mesh with Simple Collision will pass validation, but removing it and using only a Complex collision and setting Collision Complexity "Use Complex as Simple" will fail validation: "Bone None requires at least one collision shape".
UE - Simulation - Gameplay - Oct 20, 2025Context: By default, Unreal Engine creates both simple and complex shapes, then, based on what the user wants (complex query versus simple query), the physics solver will use the corresponding shape ...
Variant Manager: LevelVariantSets asset corruption after rename or duplicate
UE - Editor - Content Pipeline - Oct 24, 2025When renaming or duplicating a LevelVariantSets asset that contains a Director Blueprint, the internal DirectorClass reference becomes mismatched. Although the DirectorBlueprint pointer updates corr ...
EnumRedirections from a Blueprint enum to a c++ enum does not redirect everything correctly.
UE - CoreTech - Aug 20, 2024There is an engine bug when using the EnumRedirects feature inside a config file. If we have a Blueprint Enum used in our blueprints, and we want to convert all the Blueprint enum references to a C+ ...
Unreal Engine Fails to Launch with Vulkan SM6 RHI and RenderDoc Auto-Attach Enabled
UE - Rendering Architecture - RHI - Dec 3, 2025When launching Unreal Engine with the Vulkan RHI, SM6 and RenderDoc Auto Attach on Startup enabled, the engine fails to initialize with the error: “A compatible Vulkan Driver is required to run the ...