A Blueprint containing an array Swap node will fail to be nativized.

UE - Gameplay - Blueprint - Jul 17, 2020

Blueprint assets that utilize an array "swap" node to swap elements cannot currently be converted to C++. Current workaround: Either avoid use of the "swap" node or exclude the Blueprint asset from ...

Bake To Control Rig produces empty keys when rig uses Import Skeleton in Construction Event and binding is a spawnable in a subsequence

UE - ACT Character - Control Rig - Aug 28, 2026

Bake To Control Rig fails to key procedurally-created controls when all three of the following are true:The Control Rig creates its hierarchy at runtime via Import Skeleton in the Construction Event ...

Crash when changing "MaximumTextureSize" in "LeaveExistingMips" state

UE - Editor - Content Pipeline - Import and Export - Dec 2, 2019

No problem with 4.22.3 ...

OSVR fatal error while playing in -game

UE - Platform - XR - May 6, 2016

Found on: //UE4/Dev-VR CL-2967563 About 1/6th of the time I'd start a -game instance and go in to stereo on the OSVR, the game would seemingly just close itself. I say close as opposed to crash, si ...

Android ETC2 Debug Builds Crash on Startup

UE - Platform - Mobile - Sep 9, 2020

Android apps build with the debug configuration on ETC2 will crash on launch. ...

Editor crashed when opening TM-MeshPaint in QAGame

UE - Graphics Features - Jan 20, 2017

While reviewing [Link Removed] test case, I hit the following crash opening the TM-MeshPaint level. On first attempt shaders were compiling, on attemps after, editor crashes much faster. ...

BP - Nativization will fail at cook time if a BP class and a User-Defined Structure reference each other.

UE - Gameplay - Blueprint - Apr 20, 2017

Note: This happens with "Exclusive" nativization mode as well. This occurs because the nativized UDS 'GetDefaultValue()' method is generated into a .h file rather than a .cpp file. This creates a c ...

Loading Duplicated Level via Python API Crashes Editor

UE - Editor - Feb 16, 2023

When called from Python, in 5.1 the load level invocation results in a kernel panic style crash of the editor, with a message about the map leaking memory and not being able to be garbage collected ...

Crash when a floor mesh is removed while a Vehicle has SimulatePhysics disabled

UE - Runtime - Simulation - Sep 1, 2026

When SimulatePhysics is disabled, the constraint update is skipped, so a reference to an invalid (already-removed) particle is left behind. As a workaround, the approach suggested by the licensee — ...