For the last 6 or 7 months, I've been using a minecraft creative world. The save file appeared to be a fairly large one, compared to the others on my console. Today, when I tried to play it with a friend, after selecting a guest profile we were not able to play the game. When it was restarted and the same world was selected to open, it was unresponsive to the A button, and the little icon that was the last saves location turned into the minecraft dirt block icon. the only thing that I could do to the file was rename it; it could not be moved or copied. After a number of attempts signing in and out, and restarting the console both properly and through power interruptions, the file is still unable to be accessed.
It's unfortunate that with this console I can't go into the storage and look at each file individually, similar to the 360, so I'm really at a loss for what to do.
And it may or may not be important to note, but the time prior to this (about 14 hours ago) when I accessed the world it sync'd and worked fine.