Unreal Engine Issues
Unreal Engine Issues
Null Material Layers in Material Instances cause Opacity Mask and WPO to break on Nanite Meshes
UE - Rendering - Architecture - Materials - Oct 31, 2024When a Material Instance is loaded that has a nullptr layer in StaticParametrs.Materiallayers. The Material Instance will create it's own CachedExpressionData but the ConnectedParameterMask will be ...
AimOffset and Blenspace graphs causing crash for some users
OLD - Anim - Mar 30, 2015Users are experiencing crashes when using the AimOffset and Blendspace graphs. I am unable to reproduce this locally, but judging by the Bugg in crash reporter, this is not an isolated incident. [ ...
Nanite Landscape Visibility Layer Crash
UE - Graphics Tools - Terrain - Landscape - Jun 10, 2026Upon saving the level after creating the landscape and painting visibility, the editor crashes. When you restart the editor and load the level, you are greeted with a warning in the upper right corn ...
Staging Directory in Project Packaging Settings should not be saved as absolute path
UE - Foundation - Data Pipeline - Cooker - Jun 8, 2021When you package a project via the editor, it updates the ProjectPackagingSettings to set the StagingDirectory to the specific one chosen by the user. However, it saves this path as an absolute path ...
Preview Rendering Levels Do Not Display Supported Optimization Viewmodes in Viewport Dropdown
UE - Platform - Mobile - Apr 2, 2019When 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 ...
Crash when adding Actor Array Element to a Sequencer Event Struct
UE - Anim - Sequencer - May 25, 2017Crash 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, 2024When 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, 2017This 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 ...
FMovieSceneSkeletalAnimationParams::MapTimeToAnimation returns the wrong value if InFrameRate is not the Tick Resolution
UE - Anim - Sequencer - Jan 16, 2026FMovieSceneSkeletalAnimationParams::MapTimeToAnimation takes in an FFrameTime and FFrameRate and is supposed to tell you which frame of animation that evaluates to, when accounting for looping, play ...
[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 ...