Using dynamic bindings in a code class will result in the bindings becoming a permanent part of any Blueprint created from that class if a hot reload is performed.

UE - Foundation - Core - Mar 26, 2015

If dynamic bindings are being used in a custom code class from which Blueprints are derived, any hot reload will make the bindings a permanent part of the Blueprint and they cannot be removed or cha ...

Internal Compile error received from rearranging Format Text nodes

UE - Gameplay - Blueprint - Dec 18, 2014

Internal Compile error received from rearranging Format Text nodes Output Log of Error: LogBlueprint:Error: [compiler] Error Internal compiler error inside CreateExecutionSchedule (site 2); please ...

A project using the Script Plugin will not open in a binary version of the Engine that is created from an Engine built from source code

UE - Foundation - Build - Rocket (Installed Engine) - Feb 1, 2017

Trying to open a project that uses the Script Plugin in a binary version of the Engine that has been created from an Engine built from source code will fail. The Engine is looking for the file Unrea ...

Local binary build fails for iOS platform.

UE - Foundation - Core - Oct 5, 2017

Attempting to create a local binary build of the Engine for the iOS platform using BuildGraph is currently failing. While trying to build UHT for Mac using a remote build, the build fails because it ...

Custom UVs don't store information properly in layered materials.

UE - Rendering Architecture - Materials - May 9, 2022

[Link Removed] I have this set up so that FX artists can stack UV manipulations, so I don't want to just have all the UV manipulation in the layer with the base color, even though that does give me ...

MetalRHI Asserts When Using "Profile GPU" With RHI-Thread/Parallel-Execution

UE - Graphics Features - Sep 14, 2016

When the RHI thread is enabled (with or without parallel-execution) for Metal it isn't currently possible to run "profilegpu" because the GPU timestamp emulation code isn't multi-thread safe and pro ...

Setting spline in Niagara Override Parameters corrupts system after closing level

UE - Niagara - Mar 19, 2019

The USplineComponent appears to be corrupted. It will pass the null check, but operations done on the data cause the engine to crash. (See the linked UDN for more details) ...

EQS Overlap test no longer recognizes custom Collision Object Channel

UE - AI - Nov 12, 2019

Environment Queries Ignore tests for Custom Collision Object Overlaps. Note: The expected behavior seems to have worked in 4.21, After following the steps to reproduce, I can verify a successful de ...

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 ...

Struct with a single unaltered element will remove the element from the struct on compile

UE - Gameplay - Blueprint - Oct 7, 2015

If used inside a UMG Blueprint, a struct that has only one element will remove the element from the struct after compiling the blueprint. If the element is edited or a second element is added then ...