"'User's email address' not available in AdobeSign" when sending a document for signature with Adobe Sign

Issue
When sending a document for signing with Adobe Sign, using the Signature button, I get the error "'user's email address' not available in AdobeSign".

Cause
This is due to the following:

• When the connection to Adobe Sign was made, this was set up with Assign documents to individual users switch to "On" and the user sending the document does not have an Adobe Sign account.

Solution
Refer to Integration with Adobe Sign check if the integration is set using Assign documents to individual users switched to "On". If this is, ensure the user sending the document has an Adobe Sign account.