Exception type: EmptyPartException error in Biztalk - biztalk

Question

I am getting an error called Exception type: EmptyPartException error. My work is after the message is sent to the sendPort successfully, send an email. The Orchestration used is,
The ConstructMessage_3 constructs, SucessMessage which refers to the Multipart message SuccMsg which is of type System.Xml.XmlDocument.
Under Message_Assignment I have
SuccEmailPort(Microsoft.XLANGs.BaseTypes.Address) = "mailto:abc#gmail.com";
SucessMessage.SuccEmail = MsgVariable;
SucessMessage(SMTP.CC) = "abc#xyz.org";
SucessMessage(SMTP.Subject) = "Employee Feed";
SucessMessage(SMTP.From) = "BizTalk#sample.com";
SucessMessage(SMTP.EmailBodyText) = "The Upload Failed";
SucessMessage(SMTP.MessagePartsAttachments) = 1;
SucessMessage(SMTP.SMTPHost) = "smtp.mycompany.org";
SucessMessage(SMTP.SMTPAuthenticate) = 0;
SucessMessage(SMTP.EmailBodyTextCharset)="UTF-8";
SucessMessage.SuccEmail(Microsoft.XLANGs.BaseTypes.ContentType) = "text/plain";
SucessMessage.SuccEmail(MIME.FileName) = "emp.txt";
Here MsgVariable refers to the Variable whose type is System.Xml.XmlDocument. When tried to send the message, the message is received but not the email. It shows me error like,
xlang/s engine event log entry: Uncaught exception (see the 'inner exception' below) has suspended an instance of service 'ErrorHandling.Orchestration_1
The service instance will remain suspended until administratively resumed or terminated.
If resumed the instance will continue from its last persisted state and may re-throw the same unexpected exception.
InstanceId:
Shape name: Send_3
ShapeId:
Exception thrown from: segment 2, progress 14
Inner exception: The part 'SuccEmail' of message 'SucessMessage' contains zero bytes of data.
Exception type: EmptyPartException
Am I doing the process right or is there any other way for doing this. What is the mistake I did here. Any help would be greatly appreciated.

Answer 1

In the expression shape add
SucessMessage = new System.Xml.XmlDocument();