MIDIDeviceController.h causes compilation errors when included in an external module

UE - Audio - Jan 16, 2017

When you attempt to access MIDIDeviceController.h in your own project, it'll fail when you include it. This is the main error, while the other is a syntax error: missing type specifier - int assume ...

Content Examples: Blueprints_Overview Stand 1.7 Spark particle system does not fire from coin

Docs - Samples - Jan 19, 2017

During runtime, the red coin in Stand 1.7 on the Blueprints_Overview map of Content Examples should emit a large spark particle system 5 times. While investigating, I tried disabling "Use Fixed Rel ...

Enabling "Support Deferred Rendering with Metal" Crashes on IOS device

UE - Platform - Mobile - Feb 8, 2017

After enabling "Support Deferred Rendering with Metal" and then launching to an IOS device (in this case iphone 6+) the game will no longer open and run. REGRESSION? Yes Worked in Binary 4.13.2 C ...

Multi-Line Text metadata not available if Text variable is created in a Blueprint

UE - Gameplay - Blueprint - Feb 20, 2017

The Multi-line Text metadata specifier is not able to be set in a Blueprint. This means that text variables that are created directly inside of a blueprint cannot have this specifier set and cannot ...

Map load stalls in texture streaming code

UE - Graphics Features - Jun 13, 2017

A change was made to AActor.GetComponents which appends the results instead of resetting the output array. This seems to only impact 2 places in the code, and has a big side effect in the texture st ...

Incorrect foliage color in editor preview when using PerInstanceRandom node

Tools - Mar 19, 2018

When using PerInstanceRandom in the foliage material, the foliage in the editor preview has incorrect "broken" color. In the game preview, color shows up correctly. Reproduced in 4.19.0 CL 3944462 ...

meshes from 3ds Max which have custom pivots do not reappear in the level after undoing a delete action

UE - Editor - Content Pipeline - Datasmith - Exporters - Mar 29, 2018

There is an issue occurring where meshes from 3ds Max which have custom pivots from a datasmith import do not reappear in the level after deleting them and then undoing the delete action. The mesh d ...

Unimplemented Simplygon function causes empty mesh LODs and crashes

Tools - Aug 31, 2018

When we do the refactor for MeshDescription we miss the staticmesh reduction project settings option and change only the quadric reduction. There are two possible fixes for this issue: 1. Implemen ...

Mobile VR - Render Targets not working with Mobile Multi-View

UE - Platform - XR - Jun 6, 2019

Render target materials display as black on mobile VR when Mobile Multi-View is enabled. Also confirmed with LDR capture source. User also reports issues with scene depth (potentially fixed with [ ...

WaitMutex behaves poorly when there are casing differences in the same path

UE - Foundation - Cpp Tools - UnrealBuildTool - Jan 5, 2021

The proposed solution here is to make the casing of the path provided to the hashing function for the mutex consistent with something like:publicstatic string GetUniqueMutexForPath(string Name, stri ...