No button works on main page

I don't know what is happening but all of a sudden no buttons works on my main page in an asp.net c# application. I tried the same button and procedure on another page and it works perfectly. Where should be the problem?

and code behind

protected void Test(object sender, EventArgs e)
{
    txtTest.Attributes["class"] = txtTest.Attributes["class"].Replace("hidden", "");
}

 Main page view

<%@ Page Title="Home" Language="C#" MasterPageFile="~/Instruire.Master" AutoEventWireup="true" CodeBehind="Home.aspx.cs" Inherits="Instruire.Home" %>


    

        

            

                

                    Autentificare
                
            
            

                

                    

                        

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                            Tine-ma minte!
                        
                        

                            
                        
                    
                
            
            

                

                    

                        

                        

                            
                        
                    
                
            
        

        

            

                

                    

                        
                        
                        
                    
                
                

                    
                
            
        

        
        
        
        

        

            

                

                    
                
                

                    
                
                

                    
                
                

                    
                
                

                    
                
                

                    
                
            
            

                

                    
                
                

                    
                
                

                    
                
                

                    
                
                

                    
                
                

                    
                
            
            

                
            
        

        

              
                 
                    

                        

                            
                        
                        

                            
                        
                        

                            
                        
                        

                            
                        
                        

                            
                        
                        

                            
                        
                    
                
                    
                        

                            

                                

                                
                            
                            

                                 
                            
                            

                                
                            
                            

                                
                            
                            

                                
                            
                            

                                 
                            
                        
                  
            
        

        



    

code behind

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data.SqlClient;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace Instruire
{
    public partial class Home : Page
    {
        private readonly string connString = ConfigurationManager.ConnectionStrings["ConnString"].ConnectionString;
        protected void Page_Load(object sender, EventArgs e)
        {
            if (Session["Marca"] != null)
            {
                inputMarca.Text = Session["Marca"].ToString();
                DivUser.Attributes["class"] = DivUser.Attributes["class"].Replace("hidden", "").Trim();
                GetUserData();
                DataList1.Attributes.Add("class", "hidden");
            }
            else
            {
                inputMarca.Text = string.Empty;
                DivUser.Attributes.Add("class", "hidden");
            }

            if (HttpContext.Current.User != null && HttpContext.Current.User.Identity.IsAuthenticated)
            {
                DivLogin.Attributes.Add("class", "hidden");
                btnActualizare.Attributes["class"] = btnActualizare.Attributes["class"].Replace("hidden", "").Trim();
            }
            if (Session["SMPSI"] != null)
            {
                DivLogin.Attributes["class"] = DivLogin.Attributes["class"].Replace("hidden", "").Trim();
                DivUser.Attributes.Add("class", "hidden");
            }
        }

        protected void Check_User(object sender, EventArgs e)
        {
            GetUserData();
        }
        protected void Test_Redirect(object sender, EventArgs e)
        {
            Response.Redirect("/UserPages/Testare.aspx");
        }
        protected void Compartiment(object sender, EventArgs e)
        {

        }
        protected void GetUserData()
        {
            using (SqlConnection conn = new SqlConnection(connString))
            {
                string sqlQuery = "SELECT * FROM tblUser WHERE Marca=@Marca";
                using (SqlCommand cmd = new SqlCommand(sqlQuery, conn))
                {
                    cmd.CommandType = CommandType.Text;
                    cmd.Parameters.AddWithValue("@Marca", inputMarca.Text);

                    conn.Open();
                    using (SqlDataReader rdr = cmd.ExecuteReader())
                    {
                        if (rdr.HasRows)
                        {
                            while (rdr.Read())
                            {
                                txtMarca.Text = rdr["Marca"].ToString();
                                txtNume.Text = rdr["Nume"].ToString();
                                txtPrenume.Text = rdr["Prenume"].ToString();
                                txtCodCompartiment.Text = rdr["CodCompartiment"].ToString();
                                txtCompartiment.Text = rdr["Compartiment"].ToString();
                                txtFunctie.Text = rdr["Functie"].ToString();
                            }
                            int id = Convert.ToInt32((inputMarca.Text).ToString());

                            Session["Marca"] = id;

                        }
                        else
                        {
                            ScriptManager.RegisterClientScriptBlock(this, this.GetType(), "alertMessage", "alert('Nu este niciun user cu marca asta')", true);
                            return;
                        }
                    }
                    conn.Close();
                }
            }
        }

        protected void Get_All(object sender, EventArgs e)
        {
            GetAll();
        }
        private void GetAll()
        {
            using (SqlConnection conn = new SqlConnection(connString))
            {
                string sqlQuery = "SELECT * FROM tblUser";
                using (SqlCommand cmd = new SqlCommand(sqlQuery, conn))
                {
                    SqlDataAdapter da = new SqlDataAdapter(cmd);
                    conn.Open();
                    DataSet ds = new DataSet();
                    da.Fill(ds);
                    DataList1.DataSource = ds.Tables[0];
                    DataList1.DataBind();
                }
            }
            Session.Remove("Marca");
            DivUser.Attributes.Add("class", "hidden");
            DataList1.Attributes["class"] = DataList1.Attributes["class"].Replace("hidden", "").Trim();
        }
        protected void DataList1_ItemCommand(object source, DataListCommandEventArgs e)
        {
            if (e.CommandName == "click")
            {
                int id = Convert.ToInt32(DataList1.DataKeys[e.Item.ItemIndex].ToString());

                string marca = id.ToString();
                Session["Marca"] = marca;

                Response.Redirect("/Home.aspx");
            }
        }
        private bool ValidateUser(string userName, string passWord)
        {
            string lookupPassword = null;

            if ((null == userName) || (0 == userName.Length) || (userName.Length > 15))
            {
                System.Diagnostics.Trace.WriteLine("[ValidateUser] Input validation of userName failed.");
                return false;
            }

            if ((null == passWord) || (0 == passWord.Length) || (passWord.Length > 25))
            {
                System.Diagnostics.Trace.WriteLine("[ValidateUser] Input validation of passWord failed.");
                return false;
            }

            try
            {
                using (SqlConnection conn = new SqlConnection(connString))
                {
                    conn.Open();
                    string sqlQuery = "SELECT password FROM tblAdmin WHERE username=@userName";

                    using (SqlCommand cmd = new SqlCommand(sqlQuery, conn))
                    {
                        cmd.Parameters.Add("@userName", SqlDbType.VarChar, 25);
                        cmd.Parameters["@userName"].Value = userName;

                        lookupPassword = (string)cmd.ExecuteScalar();

                        cmd.Dispose();
                    }
                    conn.Dispose();
                }
            }
            catch (Exception ex)
            {
                System.Diagnostics.Trace.WriteLine("[ValidateUser] Exception " + ex.Message);
            }

            if (null == lookupPassword)
            {
                return false;
            }

            return (0 == string.Compare(lookupPassword, passWord, false));
        }
        protected void BTNLogin(object sender, EventArgs e)
        {
            if (ValidateUser(txtUserName.Text, txtUserPass.Text))
                FormsAuthentication.SetAuthCookie(txtUserName.Text, chkPersistCookie.Checked);
                Response.Redirect("Home.aspx");
        }
        protected void Test(object sender, EventArgs e)
        {
            txtTest.Attributes["class"] = txtTest.Attributes["class"].Replace("hidden", "");
        }
    }
}