I reinstalled the engine and it “went away”! Ghosts and spirits I guess 
[Snap! It didn’t. See logs below]
It may be related to this error: “Failed to load /Engine/EngineResources/T_Moon.T_Moon reference by MaterialExpressionTextuerObject_0”
Or this error: https://forums.unrealengine.com/unre…ure-on-startup