You have to go back to an older rootable version.
"many people asks how to root v5.0 and this was explained over and over.
You can't root this last firware with vRoot or Frameroot.
read few of my posts back and you will find a solution.
You most probably will have a link to miuiportugal web site where I have created a Tut. Use google translater if you don't understand the language of the gods, Portuguese ￼