Delta struct serialized fast arrays replicating new elements with no changelist

UE - Networking - Jun 14, 2021

There is a scenario where delta struct serialized fast arrays can replicate changes that introduce additional elements to the array, but without changelists containing the new data. This needs furt ...

Deploying from Windows to Linux fails on the first attempt

UE - Platform - Linux - Aug 3, 2017

After hitting this failure, if you try to deploy again, then it will work. This only occurs on the first attempt. Initially, I thought I hit a disc space issue I was hitting due to having a sample ...

Procedural meshes spawned at runtime cause a crash

UE - Simulation - Physics - Jan 10, 2017

When using a procedural mesh at runtime, projects fail on mobile devices. Tested on both Android Nvidia Shield and iPhone 6+. ...

Instance's parameter value for Child BP is not reflected in cooking if parent is nativized

UE - Gameplay - Blueprint - Jul 31, 2018

If an instance of a child BP has a non-default value for its parameters, that value will be ignored in the cooking process if the parent BP is nativized but the child is not and the default value fr ...

Shortcut(Ctrl+W) do a duplicate action in Blueprint Interface function list even if threre is no duplicate/copy action in the context menu.

UE - Gameplay - Blueprint - May 10, 2017

Blueprint Interface functions have no duplicate/copy context menu but still shortcut (Ctrl+W) is working and making duplicated arguments. ...

Crash when using Vertex painter with material including cubemap texture sampler

OLD - Anim - Jul 3, 2017

Engine crashes when static mesh have material with cube sampler in vertex painter mode. Simply DaylightAmbientCubemap_Mat have texture cube as texture sampler. This is not reproduced in 4.15 versi ...

Package fails after adding DesktopPlatform to public module dependency list

UE - Foundation - Core - Apr 6, 2017

Adding DesktopPlatform to the PublicDependencyModuleNames.AddRange() section of the Project.Build.cs file causes the project to fail packaging with the following error (full package logs in callstac ...

Editor crash when opening Project Settings on Linux

UE - Platform - Linux - Mar 29, 2017

When the Project Settings is opened on Linux, a call is made to run an iOS-related C# program (execute iPhonePackager certificates). This call causes the editor to crash. Unable to find mention of ...

In Sequencer, copying a Missing/Invalid Bound Object to a track may crash the Editor with an Unhandled Exception at UExporter::FindExporter()

UE - Anim - Sequencer - Jun 26, 2025

In Sequencer, copying a Missing/Invalid Bound Object to a track may crash the Editor with an Unhandled Exception at UExporter::FindExporter(). The licensee has provided a txt file that contains the ...

Reimporting Duplicated Mesh from Blender Creates Merged Meshes

Tools - Mar 26, 2018

When a mesh in Blender is Duplicated and exported as an FBX, then imported into Unreal with Combine Meshes unchecked, then both meshes reimported, one of the meshes has another mesh added to it. The ...