I have an existing contact in the system with a null id
I use SearchContactByEmail - it returns the contact
I use UpdateContactFullform to update the lists for the contact which errors out - Id cannot be null
How do I do this?
I am not aware of any reason that a contact would have a null Id. Contacts are tracked in our system by their Contact Id. Could you paste me the XML that you are receiving where it is showing you that the contact has a null id? If you would like, you can email it to the Webservices Support team.