Editor stalls on Mac after key up, mouse up

UE - Platform - Apple - Dec 19, 2019

UDN user reported a performance hit on Mac with the latest Hotfix release when the user is interacting with the editor either through keyboard or mouse input. This performance hit is noticeable whe ...

Niagara Vector Field CPU access Error prevents its use in projects

UE - Niagara - Jan 31, 2020

Niagara VectorFields do not function properly since "Fix CPU Access" changes are not persistently saved. After every Editor restart or reopening projects, the Niagara-VectorField driven Emitter and ...

Out-of-Bounds Access During Partial Updates of ISMC Per-Instance Custom Data

UE - Graphics Features - Jan 6, 2026

When using instance custom data values, removing an instance and changing the number of custom data floats in sequence can cause an array-out-of-bounds crash. The underlying arrays are not resized ...

Crash report window does not open on GitHub source builds

UE - Foundation - Core - CrashReportClient - Jun 13, 2016

When using a source build of 4.12, the crash report client window does not open even if Crash Report Client is manually built alongside the editor. UPDATE: Only affecting Source builds from Github. ...

SetMasterPoseComponent overrides any SetMorphTarget operations

OLD - Anim - Oct 16, 2015

Using Set Master Pose Component overrides any Set Morph Target operations on the slave component. ...

LIVE: Transform Variable rotation not setting correctly

UE - Gameplay - Oct 21, 2014

When trying to set the rotation value of a blueprint transform variable, changing the Y value will usually reset to 0 and change the value of X and Z as well. ...

BSP not rendering correctly on Android device Galaxy Note 2

UE - Platform - Mobile - Aug 6, 2014

Repro steps: 1. Create a new project with Third Person C++ Template. 2. Build Editor 3. Build Android 4. Cook the default map with ETC1 5. Deploy to the device and launch. No BSP is being rendered a ...

[Crash] UE4Editor-MetalRHI.dylib!ReportMetalCommandBufferFailure()

UE - Graphics Features - Jan 25, 2017

Crashes when resizing Standalone game window by dragging lower right corner to and fro to increase/decrease window size. [Link Removed] Error message: SEGV_MAPERR at 0x3 Source Context:none Mos ...

Crash when clicking on tutorial prompt for signing keys on Mac

Tools - May 2, 2017

Attempting to package for TvOS on Mac without a signing key produces an error in the message log informing the user of the missing key. The error has a link to a tutorial on how to resolve it. Click ...

Instanced Properties create temporary references on child objects in Blueprints

UE - Gameplay - Blueprint - Nov 29, 2017

When an object whose class has the EditInlineNew specifier is added to an instanced property, any children of the blueprint will have a reference to the same object that was created for the instance ...