In Microsoft Word 2010 Leveled Numbering list turns to black box

I searched some forums and got the fix, please follow the below points

1. Put your cursor on the heading just right of the black box
2. Use the left arrow key on your keyboard to move left until the black box turns grey
3. Use the keyboard combination ctrl+shift+s, the dialog "Apply Styles" should appear
4. In this box, click "reapply"