BIAB 2012

The sustained ending has quit working.... say there is no tag and on bar 8 I enter "D..." then on say bar 12 I enter a chord not used in the song {just the way I was taught long ago} "B." It should sustain but for some reason it no longer does. I would enter the number of bars in the song as 12. please help anyone?! confused hendersondouglas662@gmail.com