Erro utilizando PreparedStatement[RESOLVIDO]

Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘?)’ at line 1

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)

at java.lang.reflect.Constructor.newInstance(Constructor.java:513)

at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)

at com.mysql.jdbc.Util.getInstance(Util.java:381)

at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1030)

at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)

at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3491)

at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3423)

at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1936)

at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2060)

at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2536)

at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1564)

at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1485)

at br.com.systemcli.db.UsuarioDB.salvarUsuario(UsuarioDB.java:40)

… 1 more

Java Result: 1

public void alterarUsuario (Usuario usuario) throws SystemcliException {
        PreparedStatement stmt = null;
        AbreConsulta abs = new AbreConsulta ();
        Properties retorno = abs.AbreConsultaSQL("ArquivoSQL.properties");
        String sql = retorno.getProperty("usuario.alterar");
        Connection conn = ConnectionManager.getConexao();
        try {
            stmt = conn.prepareStatement(sql);
            stmt.setString(1, usuario.getNome());
            stmt.executeUpdate();
        }catch (SQLException e){
            throw new SystemcliException ("Erro ao alterar usuário", e);
        }finally {
           ConnectionManager.close(conn, stmt); 
        }
    }