Unreal Engine Issues
Unreal Engine Issues
Parameter metadata not accessible if modified in Material Instance and then converted to CustomPrimitiveData
UE - Rendering - Architecture - Materials - Jun 24, 2026There’s a potential issue with some changes we made to UMaterialInstance::GetParameterValue (https://github.com/EpicGames/UnrealEngine/commit/8f2bebb008ba645f5938da844cd46b0925322b13). It seems as t ...
Crash when using ListStreamingTextures with VirtualTexturePrefetchMips
UE - Rendering - Architecture - Jun 16, 2026The ListStreamingTextures command causes a crash in FRenderAssetStreamingManager::HandleListStreamingRenderAssetsCommand when there is a virtual texture that uses crashes when encountering one of t ...
Nanite Landscape Visibility Layer Crash
UE - Graphics Tools - Terrain - Landscape - Jun 10, 2026Upon saving the level after creating the landscape and painting visibility, the editor crashes. When you restart the editor and load the level, you are greeted with a warning in the upper right corn ...
Nanite: unused VertexInterpolator node disables Opacity Mask (material renders opaque)
UE - Rendering - Architecture - Jun 8, 2026On Nanite meshes, placing a VertexInterpolator node in a material graph without using it (unconnected, or routed through a disabled static switch) silently breaks the Opacity Mask and the material r ...
Mutable Dataless Generation - Regenerate Imported Models Crash
UE - Anim - Mutable - Jun 8, 2026Crash when working with Dataless Mutable content. When selecting meshes in the instance, there is a crash in RegenerateImportedModels. ...
UBackgroundBlur crashes at PSO creation under D3D12 SM6 when stereo rendering is enabled
UE - Editor - UI Systems - Slate - Jun 4, 2026Any Slate widget that triggers the Slate post-process blur (e.g., a UBackgroundBlur with non-zero strength) hits a fatal D3D12 CreateGraphicsPipelineState failure on first render. The fatal is funne ...
Crash in UWidgetAnimation::CreateDirectorInstance when switching resolution
UE - Anim - Sequencer - Jun 2, 2026Hello, We've encountered a crash in UWidgetAnimation::CreateDirectorInstance when repeatedly switching resolutions. We've had it for a while but it's not until recently that we've found a consisten ...
Instanced Actors: PCG on RuntimeGrid "None" assigns created IAManagers RuntimeGrid "MainGrid", causing cross-grid reference
UE - World Creation - Procedural Tools - PCG Graph - May 30, 2026Context PCG can be used to spawn Instanced Actors via the PCG IA Interop plugin, that makes Spawned Instanced Actors available as node. When a PCGActor placed in the level runs a PCG graph that spa ...
Instanced Actors: Moving element in editor is not undoable
UE - Engine Scaling - Mass - May 30, 2026Context Instanced Actors can be moved by unchecking Lock Instance Locations on an IAM, and double-clicking into the actor → comp → instance to select an instance. Problem Moving an IA via the giz ...
Backout attempted fix for - AutoSize triggers ensure on shortened Skel Anim Section moved past anim length
UE - Anim - Sequencer - May 29, 2026In Sequencer, calling "Edit > Auto Size" on a UMovieSceneSkeletalAnimationSection triggers the LowerBound > UpperBound ensure in UMovieSceneSection::SetRange (MovieSceneSection.h:333) when the secti ...