Zoho Sign "An unexpected error occured" when clients trying to sign documents

Zoho Sign "An unexpected error occured" when clients trying to sign documents

We are unable to have clients sign our documents. When attempting to complete the process an error appears saying "an unexpected error occured" and in the document history just shows "signing failure." We are at a complete standstill with no response from support on the issue other then to "try and refresh the page." Obviously have tried that as well as incognito windows etc and nothing is working.