Crash on iOS9 when using Apple's CFNetwork library

UE - Platform - Mobile - Dec 6, 2016

Many clients have hit a crash due to an Apple library using operator delete on a memory block that was not allocated with operator new. This happens with the following callstack on iOS9 in UE4.13 o ...

MotionWarping does not recognize new MontageInstance with the same montage

UE - MVF Character - Animation - Jan 11, 2023

When the same AnimMonotage is played again while moving with MotionWarping & RootMotion, UAnimNotifyState_MotionWarping does not recognize it. From licensee: The issue was that in URootMotionMod ...

Camera Component - Regression in Unreal 5.7+

UE - QA - Support - Oct 4, 2026

POST BODY:Summary Hey there - I’ve been sticking with Unreal Engine 5.6 for cinematics because of a regression that's been made to CineCameraActors (specifically the CameraComponent nested inside of ...

Changing a Media Player asset from Stream Mode: FromURL to From Memory crashes the editor

Tools - Dec 30, 2014

Changing a Media Player asset from Stream Mode: FromURL to From Memory crashes the editor. In 4.8, the editor crashes immediately upon changing that value, with no crash report. In 4.6 and 4.7 Pre ...

[CrashReport] UE4Editor_Core!FText::FText() [text.cpp:194]

Tools - Aug 22, 2017

This is a regular crash occurring in 4.16 and 4.17. The callstack is nearly identical to [Link Removed], which was fixed in 4.15 (different error message though). User DescriptionsImporting Files ...

[CrashReport] Linux crash - FVulkanDynamicRHI::Init()

UE - Platform - Linux - Aug 16, 2017

This is a trending Linux crash in 4.17.0 that has also occurred in 4.16 Callstack from LogLogLinux: Error: appError called: Assertion failed: Assertion failed: [File:/home/---/UnrealEngine/Engine/ ...

Open Formats: Import - Issue with importing alembic files: the skeletal mesh asset doesn't contain LOD description

UE - VEI - Open File Formats - Sep 15, 2026

Helloo everyone!! 😄 We are experiencing an issue with importing skeletal meshes from alembic. For reference, this issue happens in vanilla engine 5.7.4, but it doesn't occur in versions 5.6.x. 1) ...

Crash can occur when calling GetSkinnedVertexPosition on a skeletal mesh with a slightly different bone hierarchy than the skeletal mesh whose skeleton it is using

OLD - Anim - Apr 12, 2017

MDW: In progress (Dev-AnimPhys CL 3392820) When calling GetSkinnedVertexPosition on a skeletal mesh that uses the same skeleton as a different skeletal mesh with a slightly different bone hierarchy ...

If using SetAlignmentInViewport in Construct, the value with it is ignored

UE - AI Workflows - UI Systems - UMG - Jan 27, 2023

If SetAlignmentInViewport is called in the UMG Construct, it is ignored internally. This is due to a change that came in 5.1, so it worked fine in 5.0. First, when the Set Alignment in Viewport nod ...

Project breaks if Online Subsystem plugin is disabled

UE - Foundation - Core - Apr 25, 2017

Disabling Online Subsystem prevents the project from loading. On Windows, this produces an error shown in attached screenshot. On Linux, this causes a crash with the attached callstack on project ...