Preview Meshes in Material Instances lose their association to material on close.

UE - Rendering Architecture - Materials - Aug 13, 2015

When you assign a Preview Mesh to a Material Instance, save and close the instance, on reopening instance, the Preview Mesh will not retain connection to the Instance and will revert back to its ass ...

Extra Large Meshes Imported from Maya Flicker in Engine

UE - Simulation - Physics - Feb 16, 2015

Edit MattK: This probably has nothing to do with FBX. The object has a mass of 28 million kg so it would appear that the calculation of mass/physics asset is busted which is causing the flickering ...

UMG Visibility binding resets to default after closing and reopening project first time

UE - Editor - UI Systems - Aug 31, 2017

UMG Visibility binding resets to default after closing and reopening project first time. "Get Visibility" on Button click boolean toggle for widget blue print "False" return node value gets automa ...

Video files do not play in scene after LaunchOn to iOS from Windows

UE - Platform - Mobile - Sep 30, 2016

While attempting LaunchOn to an iOS device, the video and audio does not play. Attempts were made using the following video formats:mp4movavi Attempts were made using the following devices:iPhone 5 ...

Eyedropper in the Color Picker window does not grab any color values on Mac/Linux

UE - Graphics Features - Jan 5, 2018

Trying to use the eyedropper in the color picker window on Mac fails to grab any color values. The colors will only update when hovering or clicking within the viewport but the colors shown aren't c ...

Spawned actors with meshes become invisible in editor after changing level

UE - Graphics Features - Sep 7, 2018

When moving actors spawned from within the editor to a new sublevel, their meshes stop rendering. However, if you open a new level then re-open the old level the meshes become visible again. You wil ...

Inconsistent Red X icons when using World Composition

UE - World Creation - Worldbuilding Tools - World Composition - Sep 20, 2018

This issue takes a few attempts to repro. Sometimes when saving the icons will remain normal, but other times a red X will be displayed instead. Opening up the Level that is displaying the X and re= ...

CharacterMovementComponent causes the Character to slide when jumping on moving objects

UE - Gameplay - Player Movement - Sep 21, 2018

When the CharacterMovementComponent makes the transition from falling to walking, it retains the forward velocity it had while falling. When the character lands on the moving object, its new velocit ...

When a client sends an Unreliable RPC to the Server in same frame with a Reliable RPC, Unreliable RPCs are Reliable

UE - Networking - Sep 25, 2018

When a client sends an Unreliable RPC to the Server in same frame with a Reliable RPC, Unreliable RPCs are Reliable. It implies extremely high lag on each lost RPC and all following ones. User lose ...