Why does matchlist API sometimes work and sometimes not work?

[longi5rui]

var options = {
        rankedQueues: ['TEAM_BUILDER_DRAFT_RANKED_5x5', 'RANKED_SOLO_5X5', 'RANKED_TEAM_5X5'],
        beginIndex: 0,
        endIndex: 10
    };

    lolapi.MatchList.getBySummonerId(summonerId, options, function (error, matches) {
        // got the matches!
        console.log(matches);
    });

Most time I got matches == null But sometimes it works....

[savisaar2]

Hey mate, when you say it doesnt work does it say any error? And are you pulling from a summoner who has played games for the current season?