Xbox 360 Upload to Xbox 1 simply not working

It just says it in the screen. I've got no clue why it's happening, but it gets stuck at the end of the process. Nonetheless, it's pretty freaking annoying when your friends want to play your map, but you simply can't. Not much else to say except for the fact that there is no progress bar, and when you try to exit, it crashes the game and the console.