Javascript 无法上传文件（美国节点）

var input = $("#file-input")[0];
var file = input.files[0];
var name = file.name;
var uploadFile = new AV.File(name, file);

uploadFile.save().then(function() {
	
    // The file has been saved

}, function(error) {
	
    // The file either could not be read, or could not be saved to AV.
    console.log("Error " + error.code + ": " + error.message);

});

错误是 Error undefined: Cannot read property 'attributes' of undefined

选择的文件没有问题。这是什么原因？