textbox3 parameter is stardate
textbox4 parameter is enddate
Even though the parameters are of date, but they are being passed through a textbox text. Thus, they are mere strings (and not date even if it is of date format)
You need to convert the string into datetime and then pass on to SP. Use
Convert.ToDateTime()
or
DateTime.Parse()
for it.
Try:
this.WaybillsTableAdapter.Fill(this.DataSet1.Waybills, Convert.ToDateTime(textBox3.Text), Convert.ToDateTime(textBox4.Text), textBox1.Text);
BTW, above one is a quick fix. You should first check the text and see if correctly converted into DateTime. Further, may be you can try to use datepicker control instead of a textbox for date fields.