Error The requested URL was not found on this server

Hello, I am currently a beginner in codeiginiter and need to deliver a project CRUD in college, so far I have connected to the bank, I have listed everything. But when I click on add new error occurs, I believe it is a configuration error .. So when I click on the New Register, which is in add.php, the error occurs, nor do I know what to do ... Following:

ERROR IS HERE: link

config.php link

controllers / State.php

load-> model ('m_state', 'm');     }     function index () {         // "states" is a reference to the storage of everything that comes from "state"         $ data ['states'] = $ this-> m-> getState ();         $ this- > load- > view ('layout / header');         $ this- > load- > view ('state / index', $ data);         $ this- > load- > view ('layout / footer');     }     // Now I will create the function Add new record     public function add () {         $ this- > load- > view ('layout / header');         $ this- > load- > view ('state / add');         $ this- > load- > view ('layout / footer');     } } models / Estado_m.php db->get('estado'); if($query->num_rows() > 0){ return $query->result(); }else{ return false; } } } views / state / add.php

Adicionar Estado

" class="btn btn-success">Página Principal views / status / index.php         "class=" btn btn-success ">                                                            Code                     Name                     Initials                     Created                     options                                                            

            <tr>
                <td><?php echo $estado->idestado; ?></td>
                <td><?php echo $estado->nome; ?></td>
                <td><?php echo $estado->sigla; ?></td>
                <td><?php echo $estado->criado; ?></td>
                <td>
                    <a href="" class="btn btn-primary">Alterar</a>
                    <a href="" class="btn btn-danger">Excluir</a>
                </td>
            </tr>

            <?php 
                    }
                }    
            ?>

        </tbody>

    </table>
</code>