WinForms DataGridView set DataGridViewComboBoxCell value

Question

I have a DataGridView with custom DataGridViewComboBoxCell columns, and I run the following code to initiaize it's cells to the initial value I want:

            try
            {
                this.dgvTemplatesConfiguration.Columns.Add(this.CreateFaultsColumn(faultsData, "OuterFaults", 2));
                this.dgvTemplatesConfiguration.Columns.Add(this.CreateFaultsColumn(faultsData, "InnerFaults", 5));

            }
            catch (Exception ex)
            {
                Log.WriteLineIf(ex.Message, TraceLevel.Info);
                throw;
            }

            for (int i = 0; i < dgvTemplatesConfiguration.Rows.Count - 1; i++)
            {
                dgvTemplatesConfiguration["InnerFaults", i].Value = OkFaultName;
                dgvTemplatesConfiguration["OuterFaults", i].Value = OkFaultName;
            }

If I do it on OnLoad event, the code works fine and inits the cells, but if I run it afterwards on OnVisibleChanged event, I get an exception

DataGridViewComboBoxCell value is not valid

What is the proper way of setting default values on DataGridViewComboBoxCell?