Delete and save in table from Entity Framework

Question

Hello friends, good morning.

I have the following drawback, a many-to-many table.

works perfectly up to here, I hope it is well implemented

I show the image

 

 I enter this data in this way

 

 now i want to remove a rule from a certain profile

 

 in this case remove the Employee profile, Create Client and Edit Client. The idea I have is to delete all the rules assigned to the employee and then again enter the new rules (In this case only one rule)

 

I did this method

 

public static void InsertarPerfilRegla(tbltransPerfilRegla tbltransPerfilRegla)
        {
            using (GourmetEntities db = new GourmetEntities())
            {

                db.tbltransPerfilReglas.RemoveRange(db.tbltransPerfilReglas.Where(x => x.Perfil_Id == tbltransPerfilRegla.Perfil_Id));
                db.SaveChanges();
                db.tbltransPerfilReglas.Add(tbltransPerfilRegla);
                db.SaveChanges();
            }

        }

When I only run the code block

 

db.tbltransPerfilReglas.RemoveRange(db.tbltransPerfilReglas.Where(x => x.Perfil_Id == tbltransPerfilRegla.Perfil_Id));
               db.SaveChanges();

Works correctly

But when I run both codes it shows me an error

 

 

 This is the code in my Button

 

private void TsbGuardar_Click(object sender, EventArgs e)
        {
            tbltransPerfilRegla tbltransPerfilRegla = new tbltransPerfilRegla();
            using (GourmetEntities db = new GourmetEntities())
            {
                tbltransPerfilRegla.Perfil_Id = (int)CboPerfiles.SelectedValue;
                foreach (DataGridViewRow row in DatagridViewPerfilRegla.Rows)
                {
                    if ((bool)row.Cells["Selected"].Value)
                    {
                        //MessageBox.Show(row.Cells[1].Value.ToString());
                        tbltransPerfilRegla.Regla_Id = (int)row.Cells[1].Value;
                    }
                    tbltransPerfilRegla.InsertarPerfilRegla(tbltransPerfilRegla);
                }
            }
        }

Please can you help me to solve this problem that I have, or can you tell me another way to do this please.

I thank you very much

Rob