SAP B1 client Disconneceted due to Dmp file creation

While making sale order or invoice in sap client ,it creates a dmp file in server frequently .

Then the client got disconnected from the session, when i create a sales order or invoice (when delivery date or document date changed) for the customer to whom .dmp file created already.

Please any one advice me why this file is keep on created and how to avoid this problem.