Great question! We recommend uploading a .PDF file for greatest optimization.
1. Click on the 'Submit documentation' green box.
2. Click on the 'Replace' button within the failed file.
3. When you click 'Replace' this will take you back to your computer to upload the new file
4. Once you find the new file, click on the file and select 'Choose' or 'Open'
5. Your new file should now be visible to resubmit.