Can't add custom skins in launcher

I was trying to add a new skin to the player and kept giving me the same error "Skin images must be 64x64 or 64x32 pixel PNG files" even after checking the image size(64x64) and it is a PNG file. All the files I tried, attached below, give the same error despite "Faceless_scientist_V6.png" already being on the player.

(I don't know if it is the snapshot or not so just put the snapshot in "Affects Version/s")