hello I have seen this happen specially when using the 4gb card that comes with the tool  is like there is not enough room and something gets corrupted  while updating or swapping cards  if you have a pc with a card reader try using your pc/laptop  and  if you can get a 16 or 32 gb sd card even better  do the procedure on your computer it will be much faster and less errors also use the ethernet cable not the wireless  and erase all vehicles makes  and  download them again leave the chinese cars  for last just in case  hope this help  maybe some else can help more on this issue your having  good day