oss使用多文件上传报错

我根据阿里云js sdk的demo做了一个上传功能，使用原生的file input多文件上传，第一个文件上传成功，到第二个文件上传的时候报错：
Error: The specified upload does not exist. The upload ID may be invalid, or the upload may have been aborted or completed.

at o.<anonymous> (http://gosspublic.alicdn.com/aliyun-oss-sdk-4.10.1.min.js:4:18257)
at n (http://gosspublic.alicdn.com/aliyun-oss-sdk-4.10.1.min.js:12:806)
at Generator._invoke (http://gosspublic.alicdn.com/aliyun-oss-sdk-4.10.1.min.js:12:1851)
at Generator.e.(anonymous function) [as next](http://gosspublic.alicdn.com/aliyun-oss-sdk-4.10.1.min.js:12:985)
at n (http://gosspublic.alicdn.com/aliyun-oss-sdk-4.10.1.min.js:12:806)
at l (http://gosspublic.alicdn.com/aliyun-oss-sdk-4.10.1.min.js:12:2283)
at Generator._invoke (http://gosspublic.alicdn.com/aliyun-oss-sdk-4.10.1.min.js:12:1628)
at Generator.e.(anonymous function) [as next](http://gosspublic.alicdn.com/aliyun-oss-sdk-4.10.1.min.js:12:985)
at a (http://gosspublic.alicdn.com/aliyun-oss-sdk-4.10.1.min.js:6:28350)
at <anonymous>

请问有没有人知道怎么在js sdk重置这个upload id?

我的js功能代码：
function uploadFile(client) {

var file = document.getElementById('file').files[1];
var key = folder + file.name;
console.log(file.name + ' => ' + key);
return client.multipartUpload(key, file, {
    checkpoint: checkpoint,
    progress: progressFunc
}).catch(function (err) {
    console.log(err);
}).then(function (res) {
    console.log('upload success: %j', res);
});

}