Cannot send PDF to someone else for signature

Hey Michaelw,

We are sorry for the delay in response.

As the error message keep coming while sending the pdf for signature, so we would like to know that exactly the pdf file is is being send?

Are you using send for signature service or emailing the file to the users? And do you get the error with every document that you send or one specific one?

Try the following steps-

1- Check with a different pdf file and send to the same recipient.

2- There is a possibility that any one of the recipient email is not a valid email.

3- Check the related discussion Can't send pdf for signature 

For testing purpose you may try online via-  https://cloud.acrobat.com/sendforsignature  if that works then do share exact version of Adobe Acrobat DC you are working on.

Regards,

Akanchha