Behavior Tree (BT) services added to root nodes call the initial tick twice

UE - AI - Nov 20, 2024

Behavior Tree (BT) services added to root nodes call the initial tick twice A BT Service with the setting "Call Tick on Search Start" enabled will execute the initial tick twice when added to the ro ...

NVIDIA 5080 GPU Crash when launching City Sample with DX12

UE - Graphics Features - Lumen - Apr 16, 2025

UPDATE This issue no longer reproduces on driver versions 580.88 and higher. City Sample game crashes immediately upon opening with a NVIDIA 5080 with the latest drivers as well as some previous dr ...

Using nativized functions on buttons to spawn meshes causes assertion failure

UE - Gameplay - Blueprint - Oct 25, 2016

An assertion failure is thrown when using nativized functions on an Android device. ...

Unable to change Actor Coloration View Modes in PIE

UE - World Creation - Worldbuilding Tools - Jul 20, 2025

When in PIE changing Actor Coloration view modes from the viewport visualisation mode [Liit] -> [Actor Coloration] -> ... Does not update correctly when switching view mode and sometimes isn't corr ...

Crash when using Export All or Export Selected (UE4Editor-UnrealEd.dll!ULevelExporterFBX::ExportBinary)

Tools - Sep 21, 2017

Relates to [Link Removed] [Link Removed] Call stack is similar to the bugs above. Editor will crash when exporting assets from a level that is not dirtied. Another reproduction method is to selec ...

Adding a Scene Capture 2D to Render Target will override Motion Blur settings in level

UE - Graphics Features - Nov 24, 2014

With a Render Target From Scene Capture 2D setup in a level , the motion blur settings from a global post process volume is overridden. Was investigating Scene Captures picking up Motion Blur when ...

Lumen Global Distance Field Trace Leaking due to Surface Cache Sampling

UE - Rendering - Graphics Features - Jan 12, 2026

At 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 ...

Lighting behavior is unreliable for translucent lit materials, results are inconsistent depending on the editor camera's FOV and the editor viewport's width/height/aspect

UE - Rendering - Architecture - Oct 27, 2024

When working on the level editor viewport or testing on PIE, the visual appearance of additive/translucent lit materials changes significantly (and abruptly) when varying the camera FOV or the viewp ...

Crash caused by a race condition in Nanite::DispatchBasePass()

UE - Rendering - Graphics Features - Nanite - Feb 25, 2026

Nanite::BuildShadingCommands() launches two asynchronous tasks: ShadingCommands.SetupTask ShadingCommands.BuildCommandsTask BuildCommandsTask is responsible for modifying ShadingCommands.Commands ...

Sequencer causes 3DWidget on BP vectors to snap to Actor when active

UE - Anim - Sequencer - Nov 15, 2025

When we have Vectors in BP with Show 3D Widget enabled, the Transform Widget would always snap back to the Actor after we move the 3D Widget in-world. [Link Removed] Removing the _DaySequenceActor ...