uni-file-picker上传文件成功后再次选择上传报错errMsg: "chooseMessageFile:fail param count should be larger than 0."

<uni-file-picker   
    v-model="reportVal"   
    file-mediatype="all"  
    limit=9  
    file-extname="pdf"  
    return-type="object"  
    :disable-preview="true"  
    @select='selectUpload($event, val.orderId)'  
    @success='uploadSuccess'  
    @fail='uploadFail'  
>  
    <button class="btn uni-mb-6" :loading="uploadStatu" :disabled="uploadStatu">  
        <text v-if="val.status == 50">上传</text>  
        <text v-if="val.status == 60">更新</text>  
    </button>  
</uni-file-picker>  
<button v-if="val.status == 60" class="btn" @click="downloadVipReport(val.orderId)">查看</button>