Well when I followed the guide I used the files that were in the guide, and every after I unrooted and when back to stock, I tried to root again and that's when I kept getting the error. I re-followed the guide to root-unroot guide, and I still couldn't get the root back and I used the same .sbf file every time. Then I deleted all the files I had and tried 500 other guides with the same result. I get no /!\ when holding X and powering on, it goes straight to the screen with the android in post 16.