There was a recent update to 1.8.1 since then I cannot launch any saved worlds. I can recover worlds from my xbox one edition saves but once recovered they will not launch - with or without the texture pack active. I cannot create new worlds. I have tried launching the world's with the "play" button in the settings section and the main menu : the background pauses it's rotation as if it's going to load but nothing happens ; Same with creating new worlds. I also cannot disable the texture pack in the menu. I uninstalled minecraft and reinstalled it, and on launching the game I 'skipped' the download prompt for the texture pack and my worlds then worked. I tried reinstalling the texture pack and the problems repeat; no worlds launch, can't create new worlds  regardless if I have the texture pack active or not.