INTERFACE NOT REGISTERED Error while Reading word file in server

object missingType = Type.Missing;
                   object readOnly = true;
                   object isVisible = false;
                   object documentFormat = 8;
                   object htmlFilePath = Server.MapPath("~/Uploads/Resume/Temp/") + Resume + ".htm";
                   string directoryPath = Server.MapPath("~/Uploads/Resume/Temp/") + Resume + "_files";

                   object fileName = Server.MapPath("~/Uploads/Resume/" + Resume);//FileUpload1.PostedFile.FileName;

                   //Open the word document in background
                   ApplicationClass applicationclass = new ApplicationClass();
                   applicationclass.Documents.Open(ref fileName,
                                                   ref readOnly,ref missingType, ref missingType, ref missingType,ref missingType, ref missingType, ref  missingType,ref missingType, ref missingType, ref isVisible,ref missingType, ref missingType, ref missingType,ref missingType, ref missingType);
                   applicationclass.Visible = false;
                   Document document = applicationclass.ActiveDocument;



                   //Save the word document as HTML file
                   document.SaveAs(ref htmlFilePath, ref documentFormat, ref missingType,
                                   ref missingType, ref missingType, ref missingType,
                                   ref missingType, ref missingType, ref missingType,
                                   ref missingType, ref missingType, ref missingType,
                                   ref missingType, ref missingType, ref missingType,
                                   ref missingType);


                   //Close the word document
                   document.Close(ref missingType, ref missingType, ref missingType);

                   iframe.Attributes.Add("src", "../Uploads/Resume/Temp/" + Resume + ".htm");