Control 'ContentPlaceHolder1 name' of type 'TextBox' must be entered in a format mark with runat = server

I'm doing a job for college, a web forms application in Asp.net C#. I am having a problem and until then everything was going well, but out of nowhere is giving this error. I looked for some related stuff, and this snippet ended up "showing" my web page, but it doesn't perform any action:

public override void VerifyRenderingInServerForm(Control control){ }

Error and exceptions:

Control 'ContentPlaceHolder1_Nome' of type 'TextBox' must be entered in a format mark with runat=server.

Description: an untreated exception occurred during the execution of the current Web request. Examine the stack trace for more information about the error and where it originated in the code.

Exception details: System.Web.HttpException: control 'ContentPlaceHolder1_Nome' of type 'TextBox' must be entered in a format mark with runat=server.

Stack tracking:

[HttpException (0x80004005): control 'ContentPlaceHolder1_Nome' of type 'TextBox' must be entered in a format tag with runat=server.] System.Web.UI.Page.VerifyRenderingInServerForm (Control control) +9766490 System.Web.UI.WebControls.TextBox.AddAttributesToRender (HtmlTextWriter writer) +52 System.Web.UI.WebControls.WebControl.RenderBeginTag (HtmlTextWriter writer) +20 System.Web.UI.WebControls.TextBox.Render (HtmlTextWriter writer) +21 System.Web.UI.Control.RenderControlInternal (HtmlTextWriter writer, ControlAdapter adapter) + 66 System.Web.UI.Control.RenderControl (HtmlTextWriter writer, ControlAdapter adapter) +100 System.Web.UI.Control.RenderControl (HtmlTextWriter writer) +25 System.Web.UI.Control.RenderChildrenInternal (HtmlTextWriter writer, ICollection children) +128 System.Web.UI.Control.RenderChildren (HtmlTextWriter writer) +13 System.Web.UI.Control.Render (HtmlTextWriter writer) +12 System.Web.UI.Control.RenderControlInternal (HtmlTextWriter writer, ControlAdapter adapter) + 66 System.Web.UI.Control.RenderControl (HtmlTextWriter writer, ControlAdapter adapter) +100 System.Web.UI.Control.RenderControl (HtmlTextWriter writer) +25 System.Web.UI.Control.RenderChildrenInternal (HtmlTextWriter writer, ICollection children) +128 System.Web.UI.Control.RenderChildren (HtmlTextWriter writer) +13 System.Web.UI.Control.Render (HtmlTextWriter writer) +12 System.Web.UI.Control.RenderControlInternal (HtmlTextWriter writer, ControlAdapter adapter) + 66 System.Web.UI.Control.RenderControl (HtmlTextWriter writer, ControlAdapter adapter) +100 System.Web.UI.Control.RenderControl (HtmlTextWriter writer) +25 System.Web.UI.Control.RenderChildrenInternal (HtmlTextWriter writer, ICollection children) +128 System.Web.UI.Control.RenderChildren (HtmlTextWriter writer) +13 System.Web.UI.Page.Render (HtmlTextWriter writer) +29 System.Web.UI.Control.RenderControlInternal (HtmlTextWriter writer, ControlAdapter adapter) + 66 System.Web.UI.Control.RenderControl (HtmlTextWriter writer, ControlAdapter adapter) +100 System.Web.UI.Control.RenderControl (HtmlTextWriter writer) +25 System.Web.UI.Page.ProcessRequestMain (Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) + 1303

My Login code.aspx

<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="Login.aspx.cs" Inherits="Login_Login" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
        <div class="panel panel-default" style="width: 450px; margin: 50px 50px 50px 600px; -webkit-box-shadow: 11px 10px 65px -4px rgba(0,0,0,0.59); -moz-box-shadow: 11px 10px 65px -4px rgba(0,0,0,0.59); box-shadow: 11px 10px 65px -4px rgba(0,0,0,0.59);">
            <div class="panel-heading" style="text-align: center;">
                <h1 style="font-weight: bold;">ENTRAR</h1>
            </div>
            <div class="panel-body" style="margin: 20px 50px 20px 100px;">
                <p><span style="font-weight: bold">NOME</span></p>
                <asp:TextBox ID="Nome" Width="200px" runat="server" CssClass="form-control" placeholder="Login" aria-describedby="basic-addon1"></asp:TextBox>
                <span style="margin: 400px;"></span>
                <p>
                    <span style="font-weight: bold">SENHA</span><br />
                    <asp:TextBox ID="Senha" Width="200px" TextMode="Password" runat="server" CssClass="form-control" placeholder="Senha" aria-describedby="basic-addon1"></asp:TextBox>
                </p>
                <asp:Button ID="Entrar" runat="server" OnClick="Entrar_Click" Text="Entrar" CssClass="btn btn-primary btn-success" />
            </div>

        </div>
        <div style="text-align: center;">
            <span style="margin: 50px;">
                <asp:Label ID="Mensagem" runat="server" Visible="false" CssClass="alert alert-danger" role="alert"></asp:Label>
            </span>
        </div>
</asp:Content>

Login.aspx.cs

public partial class Login_Login : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {

        }
    }


    protected string conn = @"Data Source=PC-OSV;Initial Catalog=CadastroCompetencias;Integrated Security=True;";
    AppDatabase.SqlServerTransaction db = new AppDatabase.SqlServerTransaction();

    protected void Entrar_Click(object sender, EventArgs e)
    {
        if (ValidaUsuario(Nome.Text, Senha.Text))
        {
            // Inicializa a classe de autenticação do usuário
            FormsAuthentication.Initialize();
            //Define os dados do ticket de autenticação 
            FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(1, Nome.Text, DateTime.Now, DateTime.Now.AddMinutes(30), false, Session["Perfil"].ToString(), FormsAuthentication.FormsCookiePath);
            // Grava o ticket no cookie de autenticação
            Response.Cookies.Add(new HttpCookie(FormsAuthentication.FormsCookieName,
                 FormsAuthentication.Encrypt(ticket)));
            // Redireciona para a página do usuário
            Response.Redirect(FormsAuthentication.GetRedirectUrl(Nome.Text, false));
        }
        else
        {
            Mensagem.Visible = true;
            Mensagem.Text = "Oops... Login ou senha errados! Verifique se você não errou nada.";
        }
    }

    /// <summary>
    /// Autentica o usuário e retorna true se foi autenticado com sucesso
    /// </summary>
    protected bool ValidaUsuario(string nome, string senha)
    {
        db.ConnectionString = conn;
        DataTable tb = (DataTable)db.Query("SELECT * FROM Usuarios WHERE NomeAcesso='" + Nome.Text + "' AND Senha='" + Senha.Text + "' AND Estatus=1;");
        if (tb.Rows.Count == 1)
        {
            // Armazena na dados do usuário nas variáveis de sessão 
            Session["CodigoUsuario"] = tb.Rows[0]["CodigoUsuario"];
            Session["NomeUsuario"] = tb.Rows[0]["NomeCompleto"];
            Session["Perfil"] = "Administrador";
            return true;
        }
        else
        {
            return false;
        }
    }

}

I count on your cooperation! Grateful now!