Inconsistent accessibility: field type 'QueueCS.QueueGridHead' is less accessible than field 'QueueCS.Form1.Rightss' and how to enter the text value bind into Grid

namespace QueueCS
{
    public partial class Form1 : XtraForm
    {
        public string Queuevalue;
        public static Form1 Instance = null;
        public QueueGridHead Rightss;
 
        QueueCLib.QueueGrid qc = new QueueGrid();


        public Form1()
        {
            InitializeComponent();
            InitGrid();

        }
      
        BindingList<QueueGridHead> gridupdat = new BindingList<QueueGridHead>();
        void InitGrid()
        {
           
        }
        int id;
        private void btnPush_Click(object sender, EventArgs e)
        {

            try
            {
                //string mInfo = null;
                string mInfo = Form1.Instance.qc.PushAdd(txtRollno.Text, txtName.Text, txtContact.Text);
                mInfo = qc.PushAdd("jg", "dss", "ad");
                if (Queuevalue != "" && Queuevalue != null)
                {
                    id = -1;
                  // mInfo = Form1.Instance.qc.PushAdd("Rno", "Name", "Contact");
                   // string[] value = Queuevalue.Split('@');
                    //string[] retValue = m('^');
                    string[] retvalue = mInfo.Split('^');
                    Form1.Instance.Rightss = new QueueGridHead(retvalue[0], retvalue[1], retvalue[3]);
                    GvQueue.DataSource = gridupdat;
                    //string s1;
                  //mInfo = qc.PushAdd("jg","dss","ad");
                    //MessageBox.Show(s1);
                }
            }
            catch (Exception ex)
            {

            }
        }