Null Material Layers in Material Instances cause Opacity Mask and WPO to break on Nanite Meshes

UE - Rendering Architecture - Materials - Oct 31, 2024

When 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 ...

Lighting data wiped if sub level is hidden while rebuilding lighting for visible levels

UE - Graphics Features - Jan 11, 2017

When building lighting now you can no longer have a hidden sub level and have it retain it's built light if it was previously built. For instance, if you have a persistent level and hide the sub-lev ...

Staging Directory in Project Packaging Settings should not be saved as absolute path

UE - Foundation - Data Pipeline - Cooker - Jun 8, 2021

When 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, 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 ...

Using a Wait Delay node on Linux causes editor to immediately close without crashing

UE - Platform - Linux - Sep 14, 2015

If a call is made to the blueprint node Wait Delay the editor will immediately close during PIE when the call is made without the crash reporter appearing. The "Wait Delay" node only exists on Linu ...

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 ...

[CrashReport] UE4Editor_Core!FText::FText() [text.cpp:194]

Tools - Aug 22, 2017

This is a regular crash occurring in 4.16 and 4.17. The callstack is nearly identical to [Link Removed], which was fixed in 4.15 (different error message though). User DescriptionsImporting Files ...

[CrashReport] UE4Editor_CoreUObject!UObjectBase::IsValidLowLevelFast() [uobjectbase.cpp:294]

UE - Foundation - Core - Aug 22, 2017

This is a common crash in the 4.16 and 4.17 releases. User DescriptionsWriting a custom component in C++. Hotcompiled it through VS2017. Had the BP editor open with a class derived from that compo ...

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] Undo crash - FD3D11DynamicRHI::RHIDrawIndexedPrimitive() [d3d11commands.cpp:1650]

UE - Graphics Features - Nov 2, 2017

This is a trending crash coming out of 4.18, although it also occurred with less frequency in 4.16 and 4.17. The callstack shares similarities to [Link Removed] and [Link Removed], and the user com ...