system ver. Win10
Office ver. 2013

I need the mark in the right bar that decide to go to the last point I viewd the file when I open a word file every time. On some day it did not appear anymore after opening a new word file. But the"Shift+F5" is still working. For example: if I close file A and open it immediately, the mark will appear. But if I close file A and open a file B and close file B and then open file A, it will not appear, while the"Shift+F5" is still working.
I need this mark, because I do not want to type if I can use mouse.
Thanks for help.