OpenDocument.cs

 public dynamic OpenDocument(object fileName, object confirmConversions, object isReadOnly, object isAddToRecentFiles, object passwordDocument,
           object passwordTemplate, object isRevert, object writePasswordDocument, object writePasswordTemplate, object openFormat,
           object isVisible, object isOpenAndRepair, object docDirection, object isNoEncodingDialog, bool isScreenUpdating, bool isDisplayAlerts)
        {
            Word2.Application word = this.GetApp();

            if (word != null)
            {
                object missing = System.Reflection.Missing.Value;
                word.ScreenUpdating = isScreenUpdating;

                if (isDisplayAlerts)
                    word.DisplayAlerts = WdAlertLevel.wdAlertsAll;
                else
                    word.DisplayAlerts = WdAlertLevel.wdAlertsNone;

                object oMissing = System.Reflection.Missing.Value;

                //Document doc = word.Documents.Open(fileName, ref oMissing, isReadOnly, isAddToRecentFiles, passwordDocument, ref oMissing, ref oMissing,
                    //ref oMissing, ref oMissing, openFormat, ref oMissing, isVisible,
                    //ref oMissing, docDirection, ref oMissing, ref oMissing);

                word.Documents.Open(FileName: fileName, ReadOnly: isReadOnly, AddToRecentFiles: isAddToRecentFiles, PasswordDocument: passwordDocument, PasswordTemplate: passwordTemplate, WritePasswordDocument: writePasswordDocument, WritePasswordTemplate: writePasswordTemplate, Format: openFormat, Encoding: missing, Visible: isVisible, DocumentDirection: docDirection);
            }

            return word;
        }