Crash When Compiling Child Blueprint Containing a Custom Event with the Same Name as its Parent's Event

UE - Gameplay - Blueprint - Feb 10, 2016

Having a child blueprint that contains a custom event with the same name as a custom even that it is calling from its parent causes the editor to crash when attempting to compile the original parent ...

Soft angular constraints solve velocity like hard constraints

UE - Simulation - Core - Jul 17, 2025

Soft angular constraints are solving velocity like hard constraints. Instead of swinging back and forth, the affected body just snaps to 45 degrees. Check the steps to reproduce for more details. Th ...

[CrashReport] Assertion failed: !bRequireNormalization - UE4Editor_Landscape!ULandscapeComponent::ReplaceLayer()

UE - LD & Modeling - Terrain - Landscape - Jul 19, 2017

This is a common crash affecting users in 4.16, and has occurred since at least 4.14. Over 200 unique users have been affected, though they have provided little information. User DescriptionsI am a ...

Sampling textures with bias in the path of a custom data pin causes derivative operations when avoidable

UE - Rendering - Architecture - Materials - Apr 8, 2025

Materials that make use of the analytical derivatives path to avoid hardware derivatives can still generate derivative operations on texture samples when the shading model has a custom data pin and ...

Using xcode-select to switch between Xcode 10 and Xcode 11 beta can cause Xcode 11 to be unrecognized by the editor

UE - Platform - Apple - Jul 16, 2019

After switching from Xcode 11.0 Beta 3 (11M362v) to Xcode 10 (10A255) and then back to Xcode 11, the editor no longer recognized that Xcode was installed on my machine when trying to use Xcode 11 as ...

Crash When Copying Comment Box from a Blueprint to a Behavior Tree

UE - AI - Jun 8, 2016

The editor crashes when pasting a comment box from a blueprint into a behavior tree. Found in 4.12.1 binary. Reproduced in 4.11.2 binary and Main CL 3005971 Source Context94 95 fo ...

Packaged Game Crashes When Launched with the -dx12 for Ray Tracing Features and PixelStreaming enabled

PixelStreaming - Apr 3, 2019

Packaged game crashes when launched with the -dx12 option and PixelStreaming is enabled. Found in 4.22 CL# 5660361 and 4.23 CL# 5704223 ...

Reference to control rig can be lost on actors with multiple skeletal mesh components

UE - Anim - Rigging - Control Rig - Apr 4, 2023

In the attached project, when we initially add a control rig track for the actor with multiple skeletal mesh components, we add the control rig for the correct component because FControlRigParameter ...

Sub-world partitions do not properly handle partial editor loading as world partition standalone level instances' spatially loaded actors do not get loaded even when the Level Instance is force loaded or loaded in by region.

UE - World Creation - Worldbuilding Tools - World Partition - Aug 19, 2025

Context Level Instancing is a level-based workflow designed to improve and streamline the level editing experience. In a standalone Level Behavior, when the Level Instance Actor is loaded through it ...

Player Character does not collide with landscape

UE - LD & Modeling - Terrain - Landscape - Mar 8, 2015

UPDATE: 3/9/2015 Additional Information: User on thread https://answers.unrealengine.com/questions/186928/landscape-collison-issues-recreatelandscapecollisi.html reported workaround did not fix e ...