I’ve seen some issues recently where some PNG files do not appear correct when viewed in the Content Browser – either they’re all black or a tangle of random colors. Recently, it’s been a bunch of 64x64 icons exported from GIMP 2 with no alpha transparency. Some of the icons will load fine, but some do not. Re-importing or changing the textures’ properties does not fix this.
We seem to be able to work around this by loading the PNG files up in MS Paint and re-saving. UE4 can then load the PNG files properly every time.
Not a real problem for us since there’s a trivial workaround, but we wanted to let you know that this problem in the PNG loading code exists.
I’ve attached 2 PNG files. icon_drone_64.png seems to have the problem; icon_drone_64_2.png (the same PNG re-exported from MS Paint) does not.