D3D Crash applying Built Lighting in a level containing Static Foliage

UE - World Creation - Worldbuilding Tools - Foliage - Jun 20, 2017

Editor session crashes applying Built Lighting in a level containing Static Foliage. Note: this crash does not occur if the Instanced Foliage Mesh has mobility set to "Movable" within the Foliage D ...

Local variables in Blueprint functions don't support default values of Custom Structs

UE - Gameplay - Blueprint - Jun 9, 2015

I make a custom struct and assign default values to it's member floats, etc. When I use that in a Blueprint, the defaults work as expected. However, when I reference it as a local variable in a BP f ...

Engine Crashes When Building Lighting if Precomputed Visibility Aggressiveness is set to VIS Max

UE - Graphics Features - Nov 30, 2017

The engine crashes when building lighting if World Settings >> Precomputed Visibility >> Visibility Aggressiveness is set to "VIS Max." A Fatal Error message sometimes appears (screen shot attached) ...

Multi-line text functionality is removed from a print string variable when the variable is turned into an array within a struct

UE - Gameplay - Blueprint - May 5, 2016

Multi-line text functionality is removed from a print string variable when the variable is turned into an array within a struct. Regression (no), Multi-line text functionality for strings in struct ...

Static variable declaration causes unresolved external errors when calling FRootMotionMovementParams functions

OLD - Anim - Jan 11, 2017

Attempting to call a FRootMotionMovementParams function results in an unresolved externals error on compile because of the static FVector RootMotionScale variable. Workaround: In source, removing s ...

Crash on PIE exit after dynamically enabling and disabling tick functions through the Level Script blueprint.

UE - Gameplay - Mar 23, 2018

User reports hitting an assertion due to invalid FTickTaskManager state when game is attempting to unregister a tick function that was previously disabled dynamically. Failed assertion is in FTickT ...

Text local variables and function parameters do not store package scope properly

UE - Gameplay - Blueprint - May 14, 2019

FText variables are saved with a Package Namespace stored inside them, that keeps track of the package they were created for. This allows the translation key to stay consistent over time. Blueprint- ...

Instance overlap functions for Foliage Instanced Static Meshes detects instances inconsistently

UE - World Creation - Worldbuilding Tools - Foliage - Apr 14, 2022

Instance overlap functions for Foliage Instanced Static Meshes detects instances incorrectly. I was able to see this occur with both the Sphere and Box functions. In addition, I drew out debug sphe ...

Vector VM - Crash / memory stomp when using > 255 external function calls

UE - Niagara - Aug 12, 2025

The Vector VM has only every supported a byte's worth of external function calls, when we blew the limit it would index into the incorrect VM call. The new VM will also overwrite memory when exceed ...

Crash accessing a non-empty TSet or TMap local variable in a blueprint function

UE - Gameplay - Blueprint - Mar 6, 2017

Getting a crash when trying to access a non-empty TSet or TMap local variable in a blueprint function. This is only occurring with local variables. The issue also does not occur if the TSet or TMap ...