Adding any skin that is 64x64 or 64x32 will not work.
Latest version of the launcher.
Linked issues
is duplicated by 23
MC-275712
In the launcher for me when I try adding a skin it says only skins that are 64x64 or 64x32 pixels work even though the skin I am uploading is 64x64 pixels
Resolved
MCL-24565
I can't add a new skin in the launcher
Resolved
MCL-24568
Bug in the game laucher for new skin
Resolved
MCL-24569
Cannot upload skins to minecraft java edition
Resolved
MCL-24571
Skin not Working
Resolved
Comments 8
Can confirm in 2.29.11-1.12.3. The launcher reports that "Skin images must be 64x64 or 64x32 pixel PNG files" even when the file matches those dimensions and file type.
Fixed build is on the Beta channel right now - (go into settings and select the "beta builds" option) - and should be out on release tomorrow.
If it still doesn't work for you, use the official MC website (minecraft.net) and log in, click Change Skin in Games, and upload your desired skin. This is a hassle to do if you have a bundle of skins you want to use. (To add a skin to your skin library afterwards, restart the launcher and select "Add to library" when you have the skin uploaded and selected! 🙂)
you may be using the beta version of the launcher, try disabling this feature in the launcher settings