[CrashReport] UE4Editor_CoreUObject!FMemoryWriter::Serialize() [memorywriter.h:42]

UE - Foundation - Core - Jul 24, 2017

This is a common cook crash affecting users in 4.16. It is possibly the same issue as described in [Link Removed] for past engine versions. Source Context 33 virtual void Serialize(void* ...

Data loss caused by C++ Child Actor Component when compiling Child BP

UE - Gameplay - Blueprint - Dec 22, 2016

Having Child Actor Components that are set in code can cause data loss upon compiling the blueprint. In this particular scenario, there are two custom Actor classes involved, MainActor and SubActo ...

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 ...

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 ...

Engine Crashing with AMD R9 2 and 3 Series Cards

UE - Graphics Features - Sep 23, 2015

Multiple users are reporting crashes in the Engine when using an AMD R9 380 and 390 series cards. There was a request to have these cards added to compat lab for testing, but have not heard any upd ...

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 ...