Engine Crashes When Building Lighting if Precomputed Visibility Aggressiveness is set to VIS Max

UE - Graphics Features - Nov 30, 2017

The engine crashes when building lighting if World Settings >> Precomputed Visibility >> Visibility Aggressiveness is set to "VIS Max." A Fatal Error message sometimes appears (screen shot attached) ...

An ensure is triggered when a StaticMesh is set inside a StaticMeshComponent on an actor, and another actor references the static mesh actor from two child actor components.

UE - Framework - Blueprint - Feb 5, 2025

There is an issue when setting a Static Mesh inside a blueprint that it is referenced by another blueprint with more than one child actor. An ensure is triggered inside the engine, and there is a ...

Animation Modifiers that contain a null Animation Sequence value cause the Engine to crash when applied to an Animation Sequence

OLD - Anim - Nov 14, 2018

When an Animation Modifier passes a null Animation Sequence value to an Animation Sequence the Editor will crash. This is a regression from 4.20.3 (CL-4369336). This was reported and tested in 4.21 ...

Crash when adding a streaming level to the world through Python

UE - World Creation - Worldbuilding Tools - World Composition - Aug 3, 2021

When using the Python plugin to add an existing level as a streaming level, the editor crashes. It seems that this happens regardless of what level is added or what the contents of that level are. A ...

check(!bPostTickComponentUpdate) fails triggered by ~FStaticMeshComponentBulkReregisterContext() and FD3D12DynamicRHI::ProcessInterruptQueueUntil()

UE - Gameplay - Components - Jul 23, 2024

Context: Some ActorComponents can schedule end-of-frame work which UWorld executes later in the frame in UWorld::SendAllEndOfFrameUpdates(). By-design it appears that it's not allowed to schedule mo ...

Copying a Folder in Sequencer and later Pasting it inside Sequencer is resulting in loss of Components

UE - Anim - Sequencer - Aug 8, 2025

Copying a Folder in Sequencer and later Pasting it inside Sequencer is resulting in loss of Components. The pasted folder is not respecting the structure that was copied. This issue only happens on ...

Crash after Disabling Post Process Blueprint on a Skeletal Mesh

OLD - Anim - Aug 20, 2019

Changing the Anim Class in the Details Panel before Disable Post Process Blueprint can prevent the crash from occurring. Changing the Animation Mode does not seem to prevent this crash.  The conten ...

When Sequencer's Add Filter Menu>Keyed(U) is enabled, adding a Key to an actor that previously failed the Filter (had zero Keys) does not immediately include the Keyed actor in the filtered list (if fails FSequencerTrackFilter_Keyed::PassesFilter)

UE - Anim - Sequencer - Jun 25, 2025

When Sequencer's Add Filter Menu>Keyed(U) is enabled, adding a Key to an actor that previously failed the Filter (had zero Keys) does not immediately include the Keyed actor in the filtered list (if ...

Converting a landscape to blueprint crashes editor

UE - Gameplay - Blueprint - Sep 17, 2015

Converting a landscape to a blueprint immediately crashes the editor. Frequency: 2/2 ...