Sales Order Import through Data Management

Dear All,

I'm trying to import sales order's through Data Management.

I had successfully imported the Sales Order Header data.

When i import Sales Line Data(using entity : sales order line V2)

i'm getting the following error

"Results. update not allowed for field 'Sales order(SalesOrderNumber)'

Results. Validations failed"

Note: Number Sequence Setup against the Sales Order is set to manual.

Regards,

Manikandan.