Unreal Engine Issues
Unreal Engine Issues
[StateTree] StateTree fails to transition to the next state in child states when parent state contains some tasks
UE - AI - StateTree - Jun 12, 2026StateTree fails to transition to the next child state in a tree where the parent state has a task such as Debug Text which does not influence state completion. The ST atttempts to transition from Le ...
Possible shader preload deadlock when using Zen streaming
UE - Rendering - Architecture - Jun 12, 2026The deadlock happens when enough shader preload are launch in parallel on a slower IO backend (like zen). When that happens, the preload starts a waiting period that never ends because it cannot be ...
Custom Items and Inventory can appear enabled while actually being disabled
UE - Gameplay - Systems - Jun 10, 2026Toggling the Custom Items and Inventory setting and then closing the editor without saving can lead to a mismatch between the Project Settings Custom Items feature and the IslandSettings object in t ...
Sequencer - if you set the Take Separator to - rather than _ the New Take naming will mess up
UE - ACT Character - Sequencer - Jun 9, 2026When using a non-default take separator (eg "-") the "New Take" option produces a malformed proposed name for the take. ...
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 - Runtime - Mutable - Jun 8, 2026Crash when working with Dataless Mutable content. When selecting meshes in the instance, there is a crash in RegenerateImportedModels. ...
Niagara NDC GPU Instance Counter leak
UE - Rendering - Architecture - Niagara - Jun 5, 2026In NiagaraDataChannelData.cpp, FNiagaraDataChannelDataProxy::EndFrame enqueues a GPU readback for each entry in PendingGPUReadbackBuffers, but the corresponding FNiagaraGPUInstanceCountManager::Free ...
UBackgroundBlur crashes at PSO creation under D3D12 SM6 when stereo rendering is enabled
UE - AI Workflows - 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 - ACT Character - 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 - Graphics 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 ...