If you are seeing a black box before your heading title without the heading number being shown, you can try to fix it by reapplying the Heading style that you have selected. 

1. Place the cursor just to the right of the black box in any example of the affected heading.
2. Hit ← (left arrow) and the black box should turn gray.
3. Type Ctrl+Shift+S to bring up a style popup.
4. Select Heading 1
5. Click Reapply.

If you are still not able to correct the error, you may need to import the styles from a new version of the template or contact ETD Support (https://etd.pitt.edu/help)for asssitance.