I just replied to another post about a similar problem. Try changing the
Compatibility View if you are using IE browser. That torn paper icon at
the very top of your screen and to the left. One click and then try your
features that weren't working.
If you are using IE then it is probably the Compatibility View, that is
that torn paper icon on the very top of the screen and to the left. Give
it one click and then try your sort and other features. Good Luck.
