Mac defaults to device 0 for new Audio Mixer

UE - Audio - May 30, 2017

Users are pointing out issues with the new Audio Mixer on Macs. We have already responded on the forum post and are aware of its current state. One user has identified the issue with "default macOS ...

iOS 14.5 - Code Signing Version No Longer Supported

UE - Platform - Mobile - May 3, 2021

Using the remote build process (making an iOS build from Windows with a remote Mac) no longer functions properly on iOS 14.5 devices. It's possible to create an ipa, but it's not actually possible ...

InverseExposureLerp should return 1.0 when EYE_ADAPTION_DISABLED is 1

UE - Graphics Features - Sep 16, 2024

Materials using EyeAdaptationInverse may render incorrectly when debug visualizations are active.   This issue can be resolved by modifying the EyeAdaptionInverse function in EyeAdaptionCommon.us ...

FBX reimport issue with Interchange Framework

UE - Editor - Content Pipeline - Import and Export - Sep 15, 2025

A licensee has reported that the following repro steps can result in a "Failed to merge bones" error:One of our Skeletal Mesh assets was imported into engine version 5.4 using an older version of th ...

Renaming Parameters resets all Instances in Level and Thumbnails

UE - Rendering Architecture - Materials - Jan 27, 2015

Renaming a Parameter in a Base Material will make all instances of that Base Material in the level and the instance's thumbnail reset to default values from Base Material until the Instance is opene ...

Build Plugin process fails with null reference exception when building a plugin that has "Can Be Used With Unreal Header Tool" set to true

UE - Foundation - Cpp Tools - Dec 18, 2018

Trying to use UAT to build a plugin that has CanBeUsedWithUnrealHeaderTool set to true will fail due to a null reference exception (log from Main CL 4666322 attached). This happens because the plugi ...

[CrashReport] UE4Editor_CoreUObject!UObjectBase::IsValidLowLevelFast() [uobjectbase.cpp:294]

UE - Gameplay - Blueprint - Aug 15, 2017

This is a trending crash coming out of the 4.17 release. Users have not provided useful descriptions of their actions when the crash occurred. User Descriptionschecking stuff on internet. what does ...

FSkeletalMeshRenderData::Cache doesn't store and restore versions

UE - Anim - Rigging - Aug 18, 2022

A licensee was trying to extend the FSkelMeshSection, FSkelMeshRenderSection and USkeletalMesh serialisers with their licensee version number and found that the FSkeletalMeshRenderData::Cache functi ...

Physics object resting on movable platforms have erratic physics behavior in 4.14

UE - Simulation - Physics - Dec 14, 2016

Physics object resting on movable platforms have erratic physics behavior in 4.14. This is a regression from 4.13.2-3172292 User Description: When placing more than 10 or 20 blocks on a moving pl ...

"r.SetRes 1920x1080f" fails to set fullscreen mode when executed through blueprint node

UE - Graphics Features - Jan 19, 2016

Executing the r.SetRes _x_f command fails to set fullscreen mode when executed through blueprint node. The issue occurs when executing the command through level blueprint and an actor blueprint plac ...