Symptoms

When using docuSign "Add Document" wizard, errors out at runtime with "Data at the root level is invalid. Line 1, Position 1."
 

Diagnoses

This error typically presents itself with other wizards when a smartobject is expecting an XML structure as input, and instead gets a string.
 

Resolution

In this case, we were passing the filename property of a document to the wizard, instead of the document itself. We used the document instead of the filename, and were able to resolve the issue.