Compiler error after changing the class in a Spawn Actor from Class node, undoing with Ctrl + Z, refreshing the node, and reconnecting exposed variables

UE - Gameplay - Blueprint - May 26, 2015

Compiler error after changing the class in a Spawn Actor from Class node, undoing with Ctrl + Z, refreshing the node, and reconnecting exposed variables. "Error Internal compiler error inside Creat ...

Editor UI lightens when r.HDR.EnableHDROutput is set to 1

UE - Graphics Features - Nov 15, 2017

When console command r.HDR.EnableHDROutput = 1 is used, the entire engine UI becomes lighter or more washed out / desaturated, as shown in attached screen shots. Confirmed this bug is not present i ...

ZenGarden's game sequence doesn't play on device

UE - Platform - Mobile - Jul 18, 2017

Zen Garden loads, then the screen fades in and out as if it's ready to begin play. But when the player taps the screen, the only thing that moves are some lensflares, and the level never transitions ...

Performance drop when spawning AI actors during runtime compared to placing them in world

UE - AI - Jan 9, 2019

There is a performance difference between spawning and placing AI into a level. This is causing issues when spawning/despawning AI actors in a large open world, where 4-5ms of frame time quickly bui ...

Transform key don't visible when Import From Animation Root

UE - Anim - Sequencer - Mar 7, 2018

Transform key don't visible when Import From Animation Root. This problem happen from 4.17. 4.16 is visible. Case:4.16[Link Removed] ...

Large Landscapes cause long PIE start time delays

UE - LD & Modeling - Terrain - Landscape - Jan 29, 2020

These delays appear with large Landscapes (for example 8029 x 8029) . The delays only start occurring after the level is saved and reopened. After which PIE start times will be 5 to 15 times longer ...

Niagara color picker user parameter preview no longer updates until confirmation

UE - Niagara - Apr 18, 2025

Starting with UE 5.4, the Color Picker Tool no longer updates preview values in real time for certain editor windows like Niagara when working with User Parameters. This behavior is a regression fr ...

Crash when Reimporting SpeedTree asset with Billboard Material reset to the default World Grid Material

UE - Editor - Content Pipeline - Import and Export - Feb 7, 2017

A crash occurs when reimporting a SpeedTree asset after clearing the material billboard element and setting it to the default world grid material. The licensee reporting the issue mentions to worka ...

Animating a bone in Persona when additive curves are present, causes exponential translation

UE - Anim - Runtime - May 5, 2025

If there is an additive curve present with scalar data, and that scalar data is something like 10,10,10. When you attempt to animate the bone again the translation of the widget with translate expon ...

Compile failure packaging code project for tvOS from Mac

UE - Platform - Mobile - Apr 27, 2017

Also occurs in the live 4.15.1 build. This does not occur for BP projects or when packaging for iOS. Same compile error as UE-41313UATHelper: Packaging (tvOS): UnrealBuildTool: /Users/Shared/Unrea ...