[CrashReport] UE4Editor_ClassViewer!TBaseMulticastDelegate<void>::RemoveDelegateInstance() [delegatesignatureimpl.inl:970]

Tools - Jul 14, 2017

This is a common crash affecting users on Windows and Linux. It also appears related to an older Mac crash ([Link Removed]). Users have not provided any new descriptions. Source Context 959 ...

[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 ...

Nanite Landscape Visibility Layer Crash

UE - Graphics Tools - Terrain - Landscape - Jun 10, 2026

Upon 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 ...

No Dynamic Shadows From Stationary Lights in Forward Shading Without Building Lighting

UE - Graphics Features - Apr 24, 2018

I've observed this issue in 4.18.3 and 4.19.1. Per Licensee: So we've spotted an issue that I wanted to put on your radar with dynamic shadowed stationary lights + r.ForwardShading=1 What we're s ...

"ERROR: Client target not found!" When packaging client after enabling or disabling a plugin

Tools - Jun 5, 2018

"ERROR: Client target not found!" When packaging client after enabling or disabling a plugin. This will happen on both developer or shipping client as the build configuration.UATHelper: Packaging (W ...

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 ...