Unable to open DB file (code 14) Android SQLite

I'm using the SQLite DB on Android and I got that issue... I already put the permission "WRITE_EXTERNAL_STORAGE" and idk wtf I have to do! Plz, help me D:

Heres my code:

public static ArrayList<Livro> getLivrosWhere(String where) {
    SQLiteDatabase db = SystemDB.instance.open().db;
    Cursor cursor = db.query(TABLE_NAME, TABLE_FIELDS, where, null, null, null, "Ordem ASC");

    ArrayList<Livro> retorno = new ArrayList<Livro>();
    while (cursor.moveToNext()) {
        Livro livro = new Livro();
        livro.config(cursor);
        retorno.add(livro);
    }

    if (cursor.isLast())
        cursor.close();

    db.close();

    return retorno;
}

Broke when cursor.moveToNext()...