I'm facing this error "Value cannot be null. Parameter name: value" when i import the "docx" to richtextbox. I refer this Link for sample code. I can read below code for some file but some are not.
Here is sample Code
private void button1_Click(object sender, EventArgs e)
RadDocument document = new RadDocument();
IDocumentFormatProvider provider = new DocxFormatProvider();
OpenFileDialog openDialog = new OpenFileDialog();
openDialog.Filter = "Documents|*.docx";
openDialog.Multiselect = false;
DialogResult dialogResult = openDialog.ShowDialog();
if (dialogResult == System.Windows.Forms.DialogResult.OK)
using (Stream stream = openDialog.OpenFile())
document = provider.Import(stream);
radRichTextBox1.Document = document;
I do not know this is the file issue or not. I'm using V2011.3.11.1219 WinForms. I attached the file that can not read from code. You need to change the extension to docx.