查询位置附近对象withinKilometers出错，{ code: 304, message: ‘Database error.Code: tEkhIwWg’ }

源码：
new AV.Query('Favorite')
.equalTo('status','normal')
.exists('whereCreated')
.withinKilometers('whereCreated', new AV.GeoPoint(39.1,116.4), 20.0)
.descending('createdAt')
.skip(0)
.limit(10)
.find().then(function (favorites) {
console.log('whereCreated');
console.log(favorites.length);

}).catch(console.error);

报错：{ code: 304, message: 'Database error.Code: tEkhIwWg' }

不知道是什么原因？请大神帮忙看看！