I am having the same problem with the last measure being a quarter rest and can't be deleted. I tried giving it a time signature, moving it to previous system ( would not move), but I did notice that when I tried to use the system track "trash can" it showed a number 1 for the measure number, when in reality it was after measure 155. I also tried the "-1" in a popover. I tried changing voices to see if maybe voice 2 had something in the measure preventing it's deletion. It is on its own page - number 5. The song ends on page 4.