I keep getting this error when I try to view customer ID they have uploaded

Unfortunately, the page you were looking for could not be found. It may be temporarily unavailable, moved or no longer exists. Please check your spelling and retry.

This issue is related to the Privacy settings of your account. The Privacy option "Require log-in to view uploaded files." is checked on the Settings page, which means that you need to log in to view and download the uploaded files. 

If you want to download the uploaded files without logging in, you can uncheck the mentioned Privacy option.