Can not import my minecraft skin.

Literally can not load a skin for myself to use. Trusted skins is disabled already, but it didn't make no difference. I am trying to import a 64x64 png file, but the game for some reason says “i should upload a 64x64 png file” (see attachment). after about half an hour of going back and forth with no result i come to you with this problem that you can hopefully resolve.