I cant add a new skin

I have a problem with my game skin in Minecraft Java Edition. You see, I tried to add a new skin to my account from the Launcher and it didn't let me. The Launcher gives you the option to add a custom skin by browsing your computer and selecting the new skin file, the problem is that it doesn't accept the file for some reason I don't understand. A message appears that the files must be PNG and have a size of 64x64 or 64x32, which my files comply with perfectly, they are in PNG format and have those sizes. Below I attach a video with the problem. I would like to know why this happens.