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 ...

Spline Mesh regression on older iOS phone

UE - Platform - Mobile - Jun 10, 2019

Regression with rendering Spline Mesh Components seen on older (5s) iOS device. I did not reproduce a crash with an iPadPro A1701 or an Android Note 4 Confirmed in 4.23 MAIN at CL 6910902 ...

[CrashReport] UE4Editor_LevelEditor!FMulticastDelegateBase<FWeakObjectPtr>::RemoveAll() [multicastdelegatebase.h:81]

Tools - Oct 26, 2017

This is a trending crash in 4.18.0. One case of this callstack occurred in 4.17.1, but then numerous have occurred in 4.18. Users have not provided any descriptions of their actions when the crash ...

Crash launching ES31 app on Android

UE - Platform - Mobile - Apr 9, 2018

This has occurred so far using ES31 with Launch On to Android. It didn't occur with ES2 or Vulkan.Error: === Critical error: === Error: Error: Fatal error: [File:D:\Streams\Fortnite_Staging\Engin ...

"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 ...

[UDN-19505621] Hide Selected At Startup Issue

UE - Editor - Workflow Systems - Jun 10, 2025

From [Link Removed]: 你好,我发现这里的选项有一些工作逻辑不一致,提一个改进建议: ​ 当手动隐藏Actor小眼睛图标的时候,设置Hide Selected At Startup 是无效的,这具有很大的误导性,而其他任何情况下,工作都是正常的,比如: 1.小眼睛隐藏+Show All At Startup 2.小眼睛隐藏+Show Selected At Startup ...

[AI] Changing NavMesh Resolution in config file does not update the quantFactor of existing navmesh

UE - AI - Navigation - Aug 6, 2025

When we changed the resolution in the config, if you open a map and then look at the navmesh, the resolution it shows is the updated one from the config (assuming you haven't overridden anything) ...

NPC - Does not get updates from Material Parameter Collection changes in the editor

UE - Niagara - Sep 30, 2024

When an MPC is selected as the Source Material Collection for an NPC, all of its current parameters are carried over to the NPC with their current values. After that, if parameters are added to, rem ...

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 ...