Launcher Crashes after updating from 4.5.1 to 4.6.1

Tools - Mar 9, 2015

Launcher Crashes after updating from 4.5.1 to 4.6.1. When opening Launcher user receives the following error message: MachineId:5594134C496ADEDBDA8928BF9C26FCA5 EpicAccountId:7d0bd770cd564683863553 ...

Cooked materials and material instances size have doubled when upgrading from 5.1.0 to 5.2.0

UE - Rendering - Architecture - Materials - Jul 18, 2023

UDN: [Link Removed] A UDN customer has observed that their cooked materials have doubled in asset size going from 5.1 to 5.2. We need to investigate this is only a local issue on their side and no ...

(GAS) Block tags are ignored in version 5.5.2 if two abilities share the same parent tags structure.

UE - Gameplay - Gameplay Ability System - Feb 5, 2025

Block tags are not working correctly in version 5.5.2, it was working in 5.5.1. This is caused by a change done in version 5.5.2. The exact CL is: CL 35930696 ...

[MetaSounds][Wave Player] - 5.1 Wave Player channel output maps differently for Vorbis than other codecs

UE - Audio - MetaSounds - Aug 16, 2023

The channel output for 5.1 Waveplayer on MetaSounds is different when Platform Default (Vorbis) codec is chosen on Windows Platform Default - L, C, R, LS, RS, LFEBink, PCM, ADPCM - L, R, C, LFE, LS ...

Regression: "Object Position" node in Light Function materials did not compile up to UE 5.0. Starting with 5.1, it compiles but outputs garbage values

UE - Rendering - Architecture - Materials - Aug 26, 2024

Up to UE 5.0, when the "Object Position" node is used in the Material Editor as part of a material with Light Function domain, attempting to compile the material results in the following error: "[SM ...

Mutable custom versioning issue from 5.5->5.6

UE - Runtime - Mutable - Sep 19, 2025

In 5.6, a handful of new entries in `FCustomizableObjectCustomVersion` were added, including `SetDisplayNamePropertyAsPinNameOfTableNodes`. Looking back at the history, `SetDisplayNamePropertyAsPinN ...

Content Examples: Example 1.5 is stiff in Cloth Map

Docs - Samples - Apr 26, 2017

Example 1.5 on Cloth Map seems very stiff in 4.16 compared to 4.15. Regression: Yes Works in 4.15 ...

Actor scale can be different on client and server when spawning with scale of (1,1,1)

UE - Networking - Feb 28, 2023

When spawning an actor, we don't seem to replicate the scale if it's set to (1,1,1), even if the root component's default scale is different to this. This results in the client using the default sca ...

Object Mixer shows actors the World Outliner hides (5.8 is incompatible with 5.7-and-earlier behavior)

UE - CAPT - Tools - Aug 25, 2026

For the same project and the same filter, Object Mixer returns a different set of actors on 5.8 than it does on 5.7. Actors that the World Outliner hides now appear in the Object Mixer list. Editor ...

Merging Splines causes Engine to Crash in 5.1

UE - Engine Scaling - Streaming - Merge Actor - Dec 15, 2022

Attempting to merge two spline actors causes the Engine to crash. This issue occurs with the Steps to Reproduce regardless if there are more branches added to the tree branch spline/enabled, and reg ...