Actor Component Replication Not Working on Dynamically Spawned Components in Blueprint

UE - Networking - Aug 7, 2018

Actor components that are spawned dynamically through Blueprint are not being properly replicated to the client.  Found in 4.20 CL# 4233996 and reproduced in 4.21 Main CL# 4258917 Unable to test i ...

[CrashReport] UE4Editor_CoreUObject!FCompressedChunk::FCompressedChunk()

UE - Foundation - Core - Jul 24, 2017

This is a common crash affecting users in 4.16 and the 4.17 Previews. The two descriptions provided by users say their crash occurred after updating their project from 4.13. User DescriptionsUpgra ...

Unreal crashes when you connect scalar node to scalar input, when material function has a vertex interpolator

UE - Graphics Features - Mar 19, 2018

There is an issue occurring where Unreal crashes when you connect a scalar node to scalar input when the material function has a vertex interpolator. This issue causes the engine to crash, but the i ...

Disabled Skeletal Mesh Sections cause Shadow Ray Tracing Flicker

UE - Graphics Features - Ray Tracing - Dec 12, 2025

If a skeletal mesh has a section disabled the ray traced shadow will flicker when the camera or itself moves. Previously in 5.6.0 no raytraced shadow would appear if a section was disabled. This wa ...

Renaming native struct with redirect can break user defined structs

UE - Gameplay - Blueprint - Jul 18, 2018

From https://udn.unrealengine.com/questions/444690/redirecting-ustruct-used-as-member-of-userdefineds.html In 4.20 it was changed so soft object ptrs pointing to classes work correclty with +ClassR ...

Datasmith files containing special characters do not import correctly in Unreal

UE - Editor - Content Pipeline - Datasmith - Exporters - Oct 10, 2018

User is experiencing an import issue with a 3DS Max 2019 file. Their workflow is as follows and works for all their assets but this one:Original file created in revit 2019Import revit link to 3dsmax ...

Crash when quick binding a function in a class that extends LevelSequenceDirector

UE - Anim - Sequencer - Sep 16, 2020

The purpose was to create a Level Sequence Director inheritance class so that the same event could be reused in multiple sequencers. Attempting to quick-bind this base Level Sequence Director event ...

PCG crash when using Attribute Remove Duplicates on partitioned data if one of those sets of data is empty

UE - World Creation - Procedural Tools - PCG Graph - Jul 3, 2025

Context: In PCG, the Attribute Remove Duplicates node can be used to remove duplicate attributes from an array. Problem: The licensee has observed that using the Attribute Remove Duplicates node ...

FIndexedCurve::ScaleCurve returns invalid results

UE - Anim - Runtime - Feb 13, 2025

Calling SetKeyTime in iterating KeyHandlesToIndices array can modify the array order, so it breaks the iterator. Perhaps ShiftCurve also has the same problem. Here is a work around: void FIndexedCu ...

Dirty Actors in WP lose their actor folder in the outliner (and cause warnings) on PIE

UE - World Creation - Worldbuilding Tools - World Partition - Mar 20, 2023

From Licensee: You can reproduce this in stock by doing the following:Make a new 5.1 project with a new WP map (it can be empty)Put some actors in some folders in the outliner and save them/reload ...