Value cannot be null. Name of parameter: entitySet

Question

I am trying to make a project of an e-commerce of Petshop in ASP.NET MVC with Entityframework. Everything was going well, until suddenly, when I tried to register or even list Vendor, this error appeared:

[ArgumentNullException: Valor não pode ser nulo. Nome do parâmetro: entitySet]

One day it was working super well, and the next day it just wasn’t. I tried to fix it by going through Connectionstring, Identitymodels and Dbmodels:

Web.config (Connectionstring):

  <connectionStrings>
   <add name="Conexao" connectionString="server=localhost;user id=root;password=12345678;persistsecurityinfo=True;database=dbpetshop" providerName="MySql.Data.MySqlClient" />
   <add name="DBModel" connectionString="server=localhost;user id=root;password=12345678;persistsecurityinfo=True;database=dbpetshop" providerName="MySql.Data.MySqlClient" />
  </connectionStrings>

Identitymodels:

public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
    public ApplicationDbContext()
        : base("DBModel", throwIfV1Schema: false)
    {
    }

    public static ApplicationDbContext Create()
    {
        return new ApplicationDbContext();
    }
}

Dbmodels:

public partial class DBModels : DbContext
{
    public DBModels()
        : base("name=DBModel")
    {
    }

    public virtual DbSet<cliente> cliente { get; set; }
    public virtual DbSet<endereco> endereco { get; set; }
    public virtual DbSet<fornecedor> fornecedor { get; set; }
    public virtual DbSet<itemvenda> itemvenda { get; set; }
    public virtual DbSet<login> login { get; set; }
    public virtual DbSet<produto> produto { get; set; }
    public virtual DbSet<venda> venda { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Entity<cliente>()
            .Property(e => e.NomeCli)
            .IsUnicode(false);

        modelBuilder.Entity<cliente>()
            .Property(e => e.CPF)
            .IsUnicode(false);

        modelBuilder.Entity<cliente>()
            .Property(e => e.RG)
            .IsUnicode(false);

        modelBuilder.Entity<cliente>()
            .Property(e => e.RG_dig)
            .IsUnicode(false);

        modelBuilder.Entity<endereco>()
            .Property(e => e.CEP)
            .IsUnicode(false);

        modelBuilder.Entity<endereco>()
            .Property(e => e.Logradouro)
            .IsUnicode(false);

        modelBuilder.Entity<endereco>()
            .Property(e => e.NomeBairro)
            .IsUnicode(false);

        modelBuilder.Entity<endereco>()
            .Property(e => e.NomeCidade)
            .IsUnicode(false);

        modelBuilder.Entity<endereco>()
            .Property(e => e.UF)
            .IsUnicode(false);

        modelBuilder.Entity<endereco>()
            .Property(e => e.CompEnd)
            .IsUnicode(false);

        modelBuilder.Entity<endereco>()
            .HasMany(e => e.cliente)
            .WithRequired(e => e.endereco)
            .HasForeignKey(e => e.IdEndCli)
            .WillCascadeOnDelete(false);

        modelBuilder.Entity<endereco>()
            .HasMany(e => e.fornecedor)
            .WithOptional(e => e.endereco)
            .HasForeignKey(e => e.IdEndFornec);

        modelBuilder.Entity<fornecedor>()
            .Property(e => e.CNPJ)
            .IsUnicode(false);

        modelBuilder.Entity<fornecedor>()
            .Property(e => e.NomeFornec)
            .IsUnicode(false);

        modelBuilder.Entity<login>()
            .Property(e => e.Usuario)
            .IsUnicode(false);

        modelBuilder.Entity<login>()
            .Property(e => e.Senha)
            .IsUnicode(false);

        modelBuilder.Entity<produto>()
            .Property(e => e.NomeProd)
            .IsUnicode(false);

        modelBuilder.Entity<produto>()
            .Property(e => e.DescProd)
            .IsUnicode(false);

        modelBuilder.Entity<venda>()
            .Property(e => e.CPF)
            .IsUnicode(false);
    }
}

But nothing worked, I tried to find also people who went through the same problem, but none of them fit with my problem. What could have happened to appear this error?