SFDC Error Unable to process due to no XML response from Salesforce

The SFDC sync error "Unable to process due to no XML response from Salesforce" or "No XML Document Error" appears.

This error means Marketo received an invalid XML response returned by SFDC. Most often, this is a transient error from SFDC and resolves on its own in the next sync cycles. 

If the error persists or is continually blocking your sync, please reach out to Marketo Support.