Removing a parameter from a blueprint function in a library can cause actor classes calling it to lose their parent or instance data

UE - Gameplay - Blueprint - Oct 4, 2018

Compile errors caused by an actor calling a function with something hooked up to a removed parameter can cause that actor to lose it's place in the hierarchy. Typically, the actor will be fixed once ...

New 'UncookedOnly' modules can incorrectly be included as a build dependency after nativization of a Blueprint asset

UE - Gameplay - Blueprint - Dec 20, 2019

The new 'UncookedOnly' module type that was added in 4.24 is not visible to Blueprint nativization, and thus it does not know to exclude these module types from the generated Build.cs file when they ...

FMath::TruncToInt() may result in incorrect data being returned in instances when a Double is passed in containing a large integer value

UE - Foundation - Core - Aug 4, 2016

The FMath::TruncToInt() function takes a float parameter, but some calls to this function pass in a double value. For most use cases, this will probably work fine. However, if the integer values are ...

Map placed actor binding to another actor's Event Dispatcher (multicast delegate) results in duplicate bindings after blueprint recompile

UE - Framework - Blueprint - Apr 17, 2025

Context Blueprint actors placed on the map can bind to another actor's event. If an ActorB has a reference to ActorA, it can bind to an event dispatcher in A by creating an event node in ActorB's e ...

Loading levels imported with World Composition's Import Tiled Landscape option from a level without World Composition enabled loads landscape components a World Origin

UE - World Creation - Worldbuilding Tools - World Composition - May 6, 2020

Landscapes created with Import Tiled Landscape are loaded at the World Origin when loaded in a level without World Composition enabled. Enabling World Composition in the second level fixes this iss ...

Moving actor to another level breaks soft object reference

UE - Gameplay - Jun 9, 2020

REGRESSION: In 4.24, there was a fixup process that would allow the soft reference to remain valid. This seems to be missing in 4.25 Moving an actor to another sublevel immediately breaks soft ref ...

Nanite displacement on landscapes not rendering on 5700XT

UE - Graphics Features - Nanite - Mar 27, 2024

This only happens on a 5700XT, tested this on the 7900XT and the issue did not occur  Initially reported on the Preview 1 forums: https://forums.unrealengine.com/t/unreal-engine-5-4-preview/1763516 ...

Cloth paint update issues

UE - Simulation - Physics - Jan 7, 2020

Activating and Deactivating Cloth Paint marks the skeletal mesh as dirty, even if no values were painted and there is no transaction in the Undo History. Painting Max Distance values from non-zero ...

Crash when destroying a geometry collection actor

UE - Simulation - Physics - Aug 7, 2020

When an actor with geometry collection is destroyed, the engine doesn't remove elements from array in the ChaosSolver So illegal references occurs. Removing element with following quick fix code ...

Undo function breaks local variables in Blueprint Function after compiling

UE - Gameplay - Oct 8, 2020

Blueprint functions appear to correctly associate local variables when renaming the function. However when undoing a rename with ctrl-z the local variables appear to lose their association. Redoing ...