【报Bug】uni.uploadFile报错：“uploadFile:fail undefined”

示例代码：

upimg(){
let _this=this;
uni.chooseImage({
count:1,
success: (chooseImageRes) => {
const tempFilePaths = chooseImageRes.tempFilePaths;
console.log(tempFilePaths[0]);
console.log(this.config+'manage/img/upload');
uni.uploadFile({
url: this.config+'manage/img/upload', //仅为示例，非真实的接口地址
filePath: tempFilePaths[0],
file:tempFilePaths[0],
name: 'img',
formData: {
img:tempFilePaths[0],
},
success: (uploadFileRes) => {
console.log(uploadFileRes.data);
let dat=JSON.parse(uploadFileRes.data)
console.log(dat)
if(dat.code==1){

                            _this.data.images.push(dat.data.url)  
                        }  

                        else{  
                            uni.showToast({  
                                title: dat.data.msg,  
                                icon:"none",  
                                duration: 1000  
                            });  
                        }  
                    },  
                    fail(err) {  
                        console.log(err)  
                    }  
                });  
            }  
        });       
        },

操作步骤：

upimg(){
let _this=this;
uni.chooseImage({
count:1,
success: (chooseImageRes) => {
const tempFilePaths = chooseImageRes.tempFilePaths;
console.log(tempFilePaths[0]);
console.log(this.config+'manage/img/upload');
uni.uploadFile({
url: this.config+'manage/img/upload', //仅为示例，非真实的接口地址
filePath: tempFilePaths[0],
file:tempFilePaths[0],
name: 'img',
formData: {
img:tempFilePaths[0],
},
success: (uploadFileRes) => {
console.log(uploadFileRes.data);
let dat=JSON.parse(uploadFileRes.data)
console.log(dat)
if(dat.code==1){

                            _this.data.images.push(dat.data.url)  
                        }  

                        else{  
                            uni.showToast({  
                                title: dat.data.msg,  
                                icon:"none",  
                                duration: 1000  
                            });  
                        }  
                    },  
                    fail(err) {  
                        console.log(err)  
                    }  
                });  
            }  
        });       
        },

预期结果：

上传图片成功

实际结果：

上传失败