Using Certain Names in Blueprint Math Expression Causes Compiler Error

UE - Gameplay - Blueprint - Aug 8, 2016

Entering a value such as x1-x0 into a math expression node is causing a compiler error in blueprints. This is inconsistent with the behavior in 4.12.5, when entering the same expression would cause ...

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 ...

Screen Space Reflection has dark artifacts at low view angles

UE - Graphics Features - Aug 23, 2016

When looking at a large flat surfaces at very sharp angles dark banding will occur at the horizon. This also occurs in 4.14 CL 3091931 Note : I've attached a 4.12.5 version of the project (SSR412) ...

Attached Project Crashes When Moving Child Actor Components in Blueprints

UE - Gameplay - Blueprint - May 3, 2016

The editor crashes when moving a child actor component in the blueprint viewport. This has not been reproduced in a clean project, and only seems to be occurring in the user project where they have ...

OnSmartLinkReached Event Not Firing in PIE

UE - AI - Sep 20, 2016

The OnSmartLinkReached event is not firing in PIE. This is a regression. In 4.12.5 the event fires as expected. Found in 4.13.0 CL 3106830 Reproduced in 4.14 Main CL 3129233. ...

Foliage instances are not included when exporting a scene to FBX

UE - World Creation - Worldbuilding Tools - Foliage - Aug 4, 2016

When exporting Foliage instances to FBX the FBX will not contain any of the foliage instances, but will include any other static or movable geometry. This is a regression. This worked in 4.11.2 but ...

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 ...

Key precision problems on some short animations

Tools - Apr 5, 2016

Please see attached UE4_anim_interp_bug.fbx for a second example. This works as expected in 4.7 and 4.8 I've got a couple different users reporting this now. I suspected animation compression to ...

Take Recorder - Viewport Freezing and Performance Degradation When Recording Without Subsequences

UE - Virtual Production - Tools - Take Recorder - Apr 11, 2024

Description: In Unreal Engine 5.4, when recording camera movements using the Take Recorder with the "Record Sources Into Sub Sequences" option turned off, significant viewport freezing and performan ...

Cannot export a Datasmith scene to the Unreal Engine project root folder on MacOS.

TM - Interoperability - Oct 29, 2024

This is mac specific. I could do the export normally on Windows with the same Twinmotion CL and UE version (5.5 preview).  It is also a regression specific to 5.5, since I've been able to export a d ...