Replication issues & warnings if a client hitches while the server seamless travels

UE - Networking - Jul 28, 2020

If a client hitches while a server performs a seamless travel, the client will get multiple lines of logspam of these warnings:Warning: UActorChannel::ProcessBunch: SerializeNewActor failed to find/ ...

CreateDynamicMaterialInstance will pull from the base rather than overridden mesh on SkinnedMeshComponent when run from construction script

UE - Framework - Blueprint - Feb 6, 2025

When UPrimitiveComponent::CreateDynamicMaterialInstance is called on a skinned mesh, and the input material is invalid, we call USkinnedMeshComponent::GetMaterial to get the base material on the exi ...

Error during packaging if nativizing a blueprint that contains a TMap with a UserDefinedEnum as a key

UE - Gameplay - Blueprint - Jun 17, 2019

Certain Map container calls (e.g. Find, Add) will fail to compile at packaging time if a Blueprint class containing a Map variable with a user-defined enumeration as the key type is nativized. This ...

Destructible cannot change collision profile at runtime via Blueprints

UE - Simulation - Physics - Destruction - Jan 6, 2015

DESCRIPTION: When attempting to change the collision profile of a destructible via Blueprints it will not set appropriately. The collision profile set via the details panel for the individual object ...

Translucent Wireframe Materials Exhibit TSR Aliasing/Crawling Due To Incorrect Velocity Rendering When Set to Output Depth And Velocity

UE - Rendering - Graphics Features - Nov 27, 2025

Note that this bug potentially also affects a wide variety of material / geometry setups; however, a translucent wireframe setup is currently the main reproduction case. The issue may also be notice ...

Crash when element is added to a map variable with unhashable key

UE - Gameplay - Mar 21, 2017

Crash when element is added to a map variable with unhashable key. An error is thrown on compile but an element can still be added under the Details panel of the variable. Crash Reporter: [Link Rem ...

AnimNotify Issue with LevelSequencer Actor with URO

UE - Anim - Runtime - Anim Blueprints - May 19, 2025

Sometimes AnimNotify does not fire when an animation is executed under the following conditions. 1. The CharacterMesh's AnimationMode uses UseAnimationAsset 2. CharacterMesh's URO is enabled (Enable ...

Updating a meshes UCX collision in an FBX will not reimport with the updated collision if it's been removed

UE - Editor - Content Pipeline - Import and Export - Jan 14, 2015

DESCRIPTION: When making a mesh with custom collision with the naming convention of UCX and exporting the FBX for use in UE4 the collision will import and update if any changes are made and reimport ...

Custom Profiles Don't Update Maps To Cook When One Is Deleted

Tools - Feb 10, 2020

If you delete a map while it is marked to be cooked in a custom profile, then run the custom profile the map won't be deleted from the profile .ulps. I wasn't able to launch using the new custom pr ...

GameInstance and subsystem initialization order is incorrect for Play In Editor

UE - Gameplay - May 18, 2023

The order of world and game instance initialization is different between a true standalone game (cooked game or an editor build with -game) and a Play In Editor game. Specifically, in Play in Editor ...