When I try to convert my world over from Xbox One edition to the better together update it converts to 2% and the crashes. The world in question is 112.3 MB in size, in the classic texture pack, medium world size and was created back on Xbox 360 version. Did some more tinketinkering with the file itself on 9/22/17 and the better together update will convert one out of my 3 worlds. One is listed above, the 3rd world doesn't even get to 1% conversion before it freezes. The game does attempt to sync up to the old minecraft data before it converts.