C# winform MS access update nov.10th corrupt my database

public Form1()
       {
           InitializeComponent();

           Refresh();
           this.dataGridView1.RowsDefaultCellStyle.BackColor = System.Drawing.Color.Bisque; // datagrid color
           this.dataGridView1.AlternatingRowsDefaultCellStyle.BackColor = System.Drawing.Color.Beige; // datagrid color

           dataGridView1.AutoResizeColumns();
           dataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells;
       }

       private void Form1_Load(object sender, EventArgs e)
       {
           // TODO: This line of code loads data into the 'rosterDataSet.Test_Trial_Roster' table. You can move, or remove it, as needed.
           this.test_Trial_RosterTableAdapter.Fill(this.rosterDataSet.Test_Trial_Roster);
           dataGridView1.AllowUserToAddRows = false;

       }


#region Button Click

       private void btn_New_Click(object sender, EventArgs e)
       {
           try
           {
               //  Edit(true);
               rosterDataSet.Test_Trial_Roster.AddTest_Trial_RosterRow(rosterDataSet.Test_Trial_Roster.NewTest_Trial_RosterRow());
               testTrialRosterBindingSource.MoveLast();
               cb_Role.Focus();
           }
           catch (Exception ex)
           {
               MessageBox.Show(ex.Message, "Message", MessageBoxButtons.OK, MessageBoxIcon.Error);
               rosterDataSet.Test_Trial_Roster.RejectChanges();
           }
       }

       private void btn_Save_Click(object sender, EventArgs e)
       {
           try
           {
               //  Edit(false);
               testTrialRosterBindingSource.EndEdit();
               test_Trial_RosterTableAdapter.Update(rosterDataSet.Test_Trial_Roster);
               dataGridView1.Refresh();


               //   maskedTextBox2.Focus();
               MessageBox.Show("You data has been Successfully saved.", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
           }
           catch (Exception ex)
           {
               MessageBox.Show(ex.Message, "Message", MessageBoxButtons.OK, MessageBoxIcon.Error);
               rosterDataSet.Test_Trial_Roster.RejectChanges();

           }
       }