Erro com o Cursor

Todas as vezes que tento iniciar a aplicação, eu recebo esse erro: java.lang.RuntimeException: Unable to start activity ComponentInfo{br.com.alura.agenda/br.com.alura.agenda.ListaAlunosActivity}: java.lang.IllegalStateException: Couldn't read row 0, col -1 from CursorWindow.Make sure the Cursor is initialized correctly before accessing data from it.

Aqui tá o método em questão:

 public List<Aluno> buscaAluno(){
        String sql = "SELECT * FROM alunos;";
        SQLiteDatabase db = getReadableDatabase();
        Cursor c = db.rawQuery(sql, null);

        List<Aluno> alunos = new ArrayList<>();
        while (c.moveToNext()){
            Aluno aluno = new Aluno();
            aluno.setId(c.getLong(c.getColumnIndex("id")));
            aluno.setNome(c.getString(c.getColumnIndex("nome")));
            aluno.setTelefone(c.getString(c.getColumnIndex("telefone")));
            aluno.setEndereco(c.getString(c.getColumnIndex("endereco")));
            aluno.setTwitter(c.getString(c.getColumnIndex("twitter")));
            aluno.setSnapchat(c.getString(c.getColumnIndex("snapchat")));
            aluno.setFacebook(c.getString(c.getColumnIndex("facebook")));
            aluno.setInstagram(c.getString(c.getColumnIndex("intagram")));
            aluno.setNota(c.getDouble(c.getColumnIndex("nota")));

            alunos.add(aluno);
        }
        c.close();
        return alunos;
    }

E aqui a activity:

 AlunoDAO dao = new AlunoDAO(this);

        List<Aluno> alunos = dao.buscaAluno();

        dao.close();


        final ListView ListaAlunos = (ListView) findViewById(R.id.lista_alunos);


        ArrayAdapter<Aluno> adaptador = new ArrayAdapter(this, R.layout.support_simple_spinner_dropdown_item, alunos);

Att, Obrigado