Unrecognized database format Error While Inserting Data With For Loop

I want to insert data from DatagridView1 to my Access (mdb) database on my Visual Basic Project. I have a large amount of data (approximately 12,000 lines) on Datagridview1. So I use a For loop to insert.

Here is my code:

   for i = 0 to Datagridview1.Rows.Count - 1
      a = Datagridview1.Rows(i).Cells(0).Value
      b = Datagridview1.Rows(i).Cells(1).Value
      c = Datagridview1.Rows(i).Cells(2).Value
      d = Datagridview1.Rows(i).Cells(3).Value
      If studentsTableAdapter.CountStudent(a, b)=0 Then
         studentsTableAdapter.Insert(a, b, "-", "New", c, 1)
      End If
      infoTxt.Text = "Saving " & i & "/" & Total
      infoTxt.Refresh()
   Next i

It works as expected, but sometimes it stops to insert and an error occurs like:

System.Data.OleDb.OleDbException (0x80004005): Unrecognized database format

This error occurs on different steps of for loops. (some times it does not occur).

Is there any reliable way to insert large amount of data from Datagridview1 to mdb database?