[Graphics] [pokeruby] Keep failing to load edited image

Hello!

I'm trying to edit move animations in pokeruby and I keep failing.

I did everything said in tutorial, decreasing color depth to 4bpp 16 colors, my picture only has 3 colors + background, userd irfanview, put background color in first position in palette, etc.

But keep getting error:

root@McPC:/mnt/c/Users/McPaul/decomps/pokeruby# make
tools/gbagfx/gbagfx graphics/battle_anims/sprites/031.png graphics/battle_anims/sprites/031.4bpp
"graphics/battle_anims/sprites/031.png" has an unsupported color type.
Makefile:279: recipe for target 'graphics/battle_anims/sprites/031.4bpp' failed
make: *** [graphics/battle_anims/sprites/031.4bpp] Error 1
root@McPC:/mnt/c/Users/McPaul/decomps/pokeruby#

Could someone help me please?

Original file is



New file is

I found it! Looks like I accidentally activated some transparency option.