The Player Heads that you got through commands doesn't work and they show the default steve skin head and when you get them through commands, the capital letters become lowercase letters; for example {SkullOwner:"Notch"} then the texture is default steve skin and the name is "notch's head" instead of "Notch's head." So REALLY ANNOYING!!!
MC-109495
Custom Player Heads do not work properly and shows the default skin head
Resolved
Invalid
0
Looks like you're playing in offline mode, inwhich case the game won't connect to the skin servers.
If your launcher says play offline, log out and log in again, it should connect to the servers again.