Verifier (the recipient of your document share) tells you they cannot see your document.
a. Ensure that if prompted, the verifier is entering their own email address (i.e. the email address to which you sent the share), NOT your own email address.
b. Ensure your share is not expired or disabled. Check this by going into:
SHARING / click on your share to view details.
From here, you can click EDIT to change your share details.