ChaosCacheManager is not reproducing Trailing Events

UE - Simulation - Core - Mar 28, 2025

ChaosCacheManager (CCM) is not reproducing Trailing Events. Particles set to track Trailing Events correctly follow the position of the trailing event when the Geometry Collection (GC) is physically ...

Clicking the GameMode Override dropdown in the World Settings tab crashes the editor

Tools - Jun 25, 2015

Clicking the GameMode Override dropdown in the World Settings tab crashes the editor. Also occurs with any of the sub-options for the GameMode. Does not appear to occur if there is not already an ex ...

Preview Rendering Levels Do Not Display Supported Optimization Viewmodes in Viewport Dropdown

UE - Platform - Mobile - Apr 2, 2019

When attempting to set an optimization viewmode while using a Preview Rendering Level other than Shader Model 5, the Optimization Viewmodes dropdown is missing all of its options and instead display ...

Fracture Mode > "Remove-On-Break" setting: Cluster Crumbling causes flickering

UE - Simulation - Visual - May 10, 2025

Fracture Mode > "Remove-On-Break" setting: Cluster Crumbling causes flickering. Once the Remove-On-Break Cluster Crumbling effect is activated, there is a small delay between the disappearance of th ...

Crash when adding Actor Array Element to a Sequencer Event Struct

UE - Anim - Sequencer - May 25, 2017

Crash when adding Actor Array Element to a Sequencer Event Struct Error message: Assertion failed: 0 [Link Removed] [Line: 56] Source Context: 42 N = FName(*StringName); 43 ...

LevelEditor: "Replace Actor" marks level as dirty even when using external actors

UE - World Creation - Worldbuilding Tools - Jul 15, 2024

When using external actors, adding/removing/replacing/editing an actor instance inside a level does not cause any modification to the Level package, which helps reduce contention for the map file on ...

[CrashReport] UE4Editor_Slate!TAttribute<FText>::Get() [attribute.h:130]

UE - Editor - UI Systems - Slate - Jul 13, 2017

This is a common crash affecting users in 4.16 User DescriptionsI imported an FBX and the editor crashed.alembic import from brekelwhats wrong with the ue4 alembic importer? Source Context 120 ...

[CrashReport][Crash] Engine!FSceneViewport::UpdateViewportRHI() [SceneViewport.cpp]

UE - Rendering - Architecture - RHI - May 29, 2026

#200 crash out of 2101 in UE 5.8 on Windows#34 crash for UE - Rendering - Architecture in UE 5.8 on Windows#20 crash for UE - Rendering - Architecture - RHI in UE 5.8 on WindowsAssertion failed: IsI ...

AutoSize triggers ensure on shortened Skel Anim Section moved past anim length

UE - Anim - Sequencer - May 26, 2026

In Sequencer, calling "Edit > Auto Size" on a UMovieSceneSkeletalAnimationSection triggers the LowerBound > UpperBound ensure in UMovieSceneSection::SetRange (MovieSceneSection.h:333) when the secti ...

Backout attempted fix for - AutoSize triggers ensure on shortened Skel Anim Section moved past anim length

UE - Anim - Sequencer - May 29, 2026

In Sequencer, calling "Edit > Auto Size" on a UMovieSceneSkeletalAnimationSection triggers the LowerBound > UpperBound ensure in UMovieSceneSection::SetRange (MovieSceneSection.h:333) when the secti ...