Crashes after destroying a skeletal mesh attached via socket name (not bone name), the destroyed mesh remains welded.

UE - Simulation - Physics - Jul 18, 2025

On welding physics bodies during primitive component attachment, UPrimitiveComponent::WeldToImplementation() calls GetRootWelded() and then GetBodyInstance() on the returned root. This searches by b ...

Crash when changing parent of Material Instance with Layered Materials and viewing Layer Parameters

UE - Rendering Architecture - Materials - Aug 1, 2025

Reparenting a MaterialInstance that uses Material Layers to another instance with a different layer configuration can cause the editor to crash when opening the Layer Parameters tab. This appears to ...

Crash when changing r.MaterialQualityLevel when FastGeo plugin enabled in cooked build

UE - World Creation - Worldbuilding Tools - Sep 5, 2025

The engine crashes when the r.MaterialQualityLevel is changed in a cooked game that uses the FastGeo Streaming Plugin. The crash doesn't repro with the same steps in Editor, just in a cooked build. ...

Pasting a folder on the Outliner while LightMixer and ViewChanges windows are open/docked crashes the Editor

UE - Virtual Production - Tools - Jun 12, 2025

When both LightMixer and ViewChanges windows are open, pasting a folder into the Outliner crashes the editor. For more detailed steps, refer to the Steps To Reproduce section. This happens whenever ...

Editor crash after reverting a Blueprint asset in source control

UE - Framework - Blueprint Compiler - Feb 26, 2025

Added context from dev support ticket:The crash occurs because FDelegateProperty::Serialize accesses a dangling SignatureFunction pointer. Given that its derefencing dangling pointers the specifi ...

AMD GPU crash with "Video memory has been exhausted" error when increasing the World Partition world and using Water Body Ocean

UE - Graphics Tools - Terrain - Landscape - Dec 8, 2022

Current steps describe the problem related to "Video memory has been exhausted (#### MB over budget). Expect extremely poor performance" on the AMD video card. In this case, the steps cause the GPU ...

Moving a saved duplicate of an OpenWorld level crashes the Editor

UE - World Creation - Worldbuilding Tools - Mar 19, 2025

Moving a saved duplicate of an OpenWorld level crashes the Editor. The act of moving the duplicated OpenWorld level crashes the Editor the moment the engine tries to delete the original level, so it ...

Python crash the engine at exit.

UE - Editor - Workflow Systems - Oct 25, 2022

A UDN reported various crashes at exit in the embedded Python library. I was able to repro the issue in Release-5.1 and trace it back at the point where python runs its garbage collection in Py_Fina ...

Crash when running "MAP REBUILD ALLVISIBLE" with hidden sublevels and then changing maps

UE - World Creation - Worldbuilding Tools - Sep 1, 2025

Running the MAP REBUILD ALLVISIBLE editor command when the current map contains hidden sublevels causes a crash upon changing maps. The issue seems to be related to hidden sublevels being cleared in ...

Variant manager crash in UPropertyValue::HasValidResolve

UE - Editor - Content Pipeline - Variants - Nov 21, 2024

in the past we have reported a lot of VM related bugs which got fixed over time. Unfortunately, I think we have another one. Right now we're using 5.0.3 binaries from the launcher. Now the pro ...