Inconsistent accessibility: field type 'QueueCS.QueueGridHead' is less accessible than field 'QueueCS.Form1.Rightss' and how to enter the textbox value stored in grid view

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>();
     
     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;
              
                 string[] retvalue = mInfo.Split('^');
                 Form1.Instance.Rightss = new QueueGridHead(retvalue[0], retvalue[1], retvalue[3]);
                 GvQueue.DataSource = gridupdat;
               
             }
         }
         catch (Exception ex)
         {

         }
     }