云开发-云函数报错，找不到问题？

{“errorCode”:1,“errorMessage”:“user code exception caught”,“stackTrace”:“Error: errCode: -1 unknown error | errMsg: downloadFile:fail [object Object]; at downloadFile api; \n    at returnAsCloudSDKError (/var/user/node_modules/wx-server-sdk/index.js:7819:16)\n    at Object.returnAsFinalCloudSDKError (/var/user/node_modules/wx-server-sdk/index.js:7833:15)\n    at Promise (/var/user/node_modules/wx-server-sdk/index.js:2676:39)\n    at process._tickCallback (internal/process/next_tick.js:68:7)”,“statusCode”:430}

不知道为什么不能用了