Try to fix SQL Exception: A new transaction is not allowed because there are other threads running in the session

Question

Here is a brief of what I try to do: there is a global temp table in SQL side that I select from it in C# wpf and I have it listed in my dataGrid DataGridIns.

I want to select some of rows by chkBox and then insert it to a table in SQL using a stored procedure.

So when I click to send SelectedRow it start as follows:

HoEntities database = new HoEntities();  //  using Entity Framework

try
{
    for (int i = 0; i < DataGridIns.Items.Count - 1; i++)
    {
        mChkBox = DataGridIns.Columns[0].GetCellContent(DataGridIns.Items[i]) as CheckBox;

        if (mChkBox.IsChecked == true)
        {
            var dataitem = DataGridIns.Items[2].ToString();
            _nullChckBox++;
            var dateSelect = DataGridIns.Columns[1].GetCellContent(DataGridIns.Items[i]) as TextBlock;
            var mainNameTBk = DataGridIns.Columns[2].GetCellContent(DataGridIns.Items[i]) as TextBlock;
            var chinCodeTBk = DataGridIns.Columns[3].GetCellContent(DataGridIns.Items[i]) as TextBlock;
            var chinNameTBk = DataGridIns.Columns[4].GetCellContent(DataGridIns.Items[i]) as TextBlock;

            var mainCodeTBk = DataGridIns.Columns[6].GetCellContent(DataGridIns.Items[i]) as TextBlock;
            var iodDescTBk = DataGridIns.Columns[7].GetCellContent(DataGridIns.Items[i]) as TextBlock;
        }

        database.sp_Ins_Main    // using stored procedure to insert into mainTable
            (mainCodeTBk.Text.Trim(), 
             mainNameTBk.Text.Trim(),
             Convert.ToInt32(chinCodeTBk.Text.Trim()),
             chinNameTBk.Text.Trim(),
             iodDescTBk.Text.Trim(),
             dateSelect.Text.Trim()
            );

            database.SaveChanges();
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.ToString());
    }
}

As I set the breakpoint and go forward step by step it reaches

database.sp_Ins_Main

and the jumps to my DataModel.Context.cs from DataModel in Entity Framework as follows:

public virtual int sp_Ins_Main(string mainCode, string mainName,
                               Nullable<int> chinCode, string chinName,
                               string iodDesc, string date)
{
        var mainCodeParameter = mainCode != null ?
            new ObjectParameter("MainCode", mainCode) :
            new ObjectParameter("MainCode", typeof(string));

        var mainNameParameter = mainName != null ?
            new ObjectParameter("MainName", mainName) :
            new ObjectParameter("MainName", typeof(string));

        var chinCodeParameter = chinCode.HasValue ?
            new ObjectParameter("chinCode", chinCode) :
            new ObjectParameter("chinCode", typeof(int));

        var chinNameParameter = chinName != null ?
            new ObjectParameter("chinName", chinName) :
            new ObjectParameter("chinName", typeof(string));

        var iodDescParameter = iodDesc != null ?
            new ObjectParameter("iodDesc", iodDesc) :
            new ObjectParameter("iodDesc", typeof(string));

        var dateParameter = date != null ?
            new ObjectParameter("Date", date) :
            new ObjectParameter("Date", typeof(string));

        return ((IObjectContextAdapter)this).ObjectContext.ExecuteFunction("sp_Ins_Main", mainCodeParameter, mainNameParameter, chinCodeParameter, chinNameParameter, iodDescParameter, dateParameter);
}

and from the line for Return ((IObjectContextAdapter)this) ... I get the error that I said in the titeld question.

System.Data.SqlClient.SqlError: New transaction is not allowed because there are other threads running in the session.

is it wrong my way that select from Temp Table and after sits in datagrid select and I just want to insert into table in Sql? how to solve this?