Promote to variable in a parent blueprint does not pass/preserve the non-default value in derived children blueprints

UE - Gameplay - Blueprint - Jul 11, 2018

When using the feature "promote to variable" on a pin that represents a value that is not an engine default (Example: Floats = 0.0, Booleans = False, ect..), that default value (for the variable tha ...

DynamicMaterialParameters Niagara module resets write flags on emitter update

UE - Niagara - Feb 4, 2026

When using the DynamicMaterialParameters Niagara module in UE 5.6, 5.7, and UE5-Main (CL 50298778), updating an emitter causes Boolean values, such as Index0Float0Write, to reset to default values, ...

Packaging fails after changing from Dynamic to Static Nav Mesh Runtime Generation

UE - AI - Feb 8, 2016

If you package with Runtime Generation set to Dynamic and then switch to Static and attempt to repackage, the packaging will fail with the following error message.[2016.02.08-16.18.14:511][217]MainF ...

Assert when having too many VR devices

UE - Platform - XR - Aug 31, 2018

Internal team is encountering a crash when adding too many VR devices. Email thread titled "Re: Crash Logs" The bug is an internal limit of devices the code supports, which is 8. If a controller o ...

TArray64 RangeCheck prints the incorrect error messages for values over 32-bit length

UE - CoreTech - Apr 27, 2022

TArray64 RangeCheck prints the incorrect error messages for values over 32 bit. Repro Rate: 4/4 Tested this in //UE4/Release-4.27 @ CL#18319896 and the issue did occur there, it is not a regressi ...

Memory Usage Remains High After Exiting PIE

Tools - Nov 24, 2015

Originally, a project that uses about 500 mb of memory spikes to over 2 gigs during PIE. After exiting PIE, the memory usage remains well over 2 gigs and continues to rise. Found in 4.10 Binary. R ...

Crumbling Geometry Collections do not render for one frame when child clusters crumble

UE - Simulation - Physics - Destruction - Oct 3, 2024

Crumbling Geometry collection do not render for one frame when child clusters crumble. In the repro project a 4 particle GC is told to crumble. The single GeometryCollectionActor is then split into ...

Physics Constraint Component loss of accuracy

UE - Simulation - Physics - Mar 6, 2025

Physics Constraint Component has lost accuracy between Unreal versions 5.2 and 5.4 (and up). When measuring the exact distance between rigid bodies constrained by a Physics Constraint Component, the ...

Detour AI Controller Not Functioning Properly

UE - AI - Oct 30, 2015

Using AI Detour in 4.9.2 works as expected, however, when upgrading a project from 4.9.2 to a newer version, the AI pawns fail to properly navigate around each other when moving to their respective ...

Splash screen on iOS is stretched

UE - Platform - Mobile - Dec 22, 2015

The splash screen on the iPhone 6s is stretched when loading. Tested alongside the iPhone 5s and the Samsung Galaxy Note 2 for comparison. The stretching only occurs on the 6s. iPhone 6s: 6240_iPho ...