Looks like this is being called from here:. This is the only result from Sublime in Engine/Source folder.
Engine/Source/Runtime/CinematicCamera/Private/CineCameraComponent.cpp
Code is:
static ConstructorHelpers::FObjectFinder<UMaterial> PlaneMat(TEXT("/Engine/EngineDebugMaterials/M_SimpleTranslucent.M_SimpleTranslucent"));
FocusPlaneVisualizationMaterial = PlaneMat.Object;
But I have no idea why my project tries to launch a CineCameraComponent. I don’t have something like this. No occurences from search via Sublime Text.
Also, even if I apply M_SimpleTranslucent material to an object in my game, it shows WorldGridMaterial when packaged for iOS.