If you receive the following error message while processing an order:
<<*>>ERROR MESSAGES (response)|*|Customer: Failed to update Sage CRM with customer number 'WEB00XXXX', named 'Starbucks'. Specific error: System.InvalidOperationException: There is an error in XML document (1, 3510). --->
First attempt to restart your server. If that does not resolve the issue, please contact commercebuild Customer Success.