Packaging fails with too many instanced static meshes

Rendering - Jun 8, 2018

Project will fail to package with more than one actor containing ISM Components. From user: "...After some testing I found that it only occurs if there are multiple actors in a map (either of the ...

Cannot access properties of the FAppleARKitFrame struct from within a Blueprint

Virtual Reality - Jun 8, 2018

It is not possible to access properties of the {FAppleARKitFrame}} struct within a Blueprint. The struct itself is exposed as a BlueprintType, but none of its properties are also exposed. ...

Crash Occurs When Importing a .ABC File as Skeletal Mesh Into Project That Already Contains Asset's Materials

Anim - Jun 8, 2018

Editor crashes when importing an .abc file as a skeletal mesh and the assets materials already exist inside the project. -Materials need exist inside project before import -If the .abc file is imp ...

Welded grandchildren do not overlap properly when their grandparent is simulating physics

Physics - Jun 7, 2018

Grandchildren (C in an attachment hierarchy of A < B < C) that are auto welded have issues related to overlap events when moving via physics. They tend to overlap later than they should. This does n ...

Camera Actor variable (array) no longer editable in Blueprints

Gameplay - Jun 7, 2018

This is a regression from 4.19. In 4.19 you were able to change the actor assigned to the array element in a Camera Actor variable. In 4.20 and 4.21 the field is grayed out and displays None with a ...

Unlit view is affected by Exposure Compensation when enabled by post process volume

Rendering - Jun 7, 2018

Unlit view is affected by Exposure Compensation when enabled by post process volume. This will also carry across the other debug views.  Working as expected in 4.18 CL# 3832480 Found in  4.19 CL# ...

Duplicating Level With Large _BuiltData File Results in Editor Crash

Core - Jun 7, 2018

Trying to duplicate a level in the editor that has a large _BuiltData file results in a crash. In the case of the supplied test level, it is over 3 GB. Crash repros in 4.19.2 and Main (CL 4115885). ...

4.20p1 Niagara System & Emitter windows missing compile icon with small toolbar icons

Rendering - Niagara - Jun 7, 2018

in the Niagara System & Emitter windows the compile button will be missing if small toolbar icons is enabled. The icons work correctly if this is not enabled. Found in 4.19 CL# 4033788, 4.20p1 CL# ...

Crash when adding Emitter in parameters in Niagara

Rendering - Niagara - Jun 7, 2018

When adding an emitter to a Niagara System, in 4.20 Preview 1, the Editor freezes up and crashes. ...

Placing a rect light in between two static meshes causes the surface to be extremely bright

Rendering - Jun 7, 2018

Placing a rect light in between two static meshes causes the surface to be extremely bright. This will happen even though the lights settings are default. It will not happen if it is lighting just a ...