If your proof shows black boxes, there may be an element in the file that the system is having trouble processing. You can often resolve this by using the crop tool and following these steps:
Step 1: Click the Edit icon
Step 2: Drag the frame to reposition it over your image
Step 3: Click the green Save button—the window will close automatically
Step 4: Select Review Customization to view your updates
This process re-saves the image in the system, which typically resolves the issue and allows it to display correctly on your proof.