我按照https://github.com/tomitrescak/meteor-uploads上的行教程行，在上传达到100％后立即获得503服务不可用。 js控制台日志说/上传丢失但我不知道这意味着什么
render.change file: IMG_4180.JPG
uploader.js:167 render.add
jquery.js:9659 POST http://treehacks.cloudapp.net:3000/upload 503 (Service Unavailable)
uploader.js:200 render.fail
uploader.js:82 data.sumbit.fail: Unexpected error. 503 Service Unavailable
uploader.js:85 data.sumbit.always: textStatus= error
sockjs-0.3.4.js:854 GET http://treehacks.cloudapp.net:3000/sockjs/info?cb=on9gi8aoej 503 (Service Unavailable)
sockjs-0.3.4.js:854 GET http://treehacks.cloudapp.net:3000/sockjs/info?cb=esmeje0lui 503 (Service Unavailable)
sockjs-0.3.4.js:854 GET http://treehacks.cloudapp.net:3000/sockjs/info?cb=us0wyblu2e 503 (Service Unavailable)
同时，服务器崩溃，之后只提供错误页面。在服务器日志中，我得到了
W20150222-01:49:32.150(0)? (STDERR) app/meteor.js:57
W20150222-01:49:32.159(0)? (STDERR) return formData.contentType;
W20150222-01:49:32.159(0)? (STDERR) ^
W20150222-01:49:32.264(0)? (STDERR) TypeError: Cannot read property 'contentType' of undefined
W20150222-01:49:32.275(0)? (STDERR) at Object.UploadServer.init.getDirectory (app/meteor.js:57:23)
W20150222-01:49:32.275(0)? (STDERR) at IncomingForm.<anonymous> (packages/tomi:upload-server/upload_server.js:326:1)
W20150222-01:49:32.275(0)? (STDERR) at IncomingForm.emit (events.js:98:17)
W20150222-01:49:32.275(0)? (STDERR) at /home/treehacks/.meteor/packages/tomi_upload-server/.1.2.1.uqdd2s++os+web.browser+web.cordova/npm/node_modules/formidable/lib/incoming_form.js:228:12
W20150222-01:49:32.276(0)? (STDERR) at WriteStream.<anonymous> (/home/treehacks/.meteor/packages/tomi_upload-server/.1.2.1.uqdd2s++os+web.browser+web.cordova/npm/node_modules/formidable/lib/file.js:70:5)
W20150222-01:49:32.276(0)? (STDERR) at WriteStream.g (events.js:180:16)
W20150222-01:49:32.276(0)? (STDERR) at WriteStream.emit (events.js:117:20)
W20150222-01:49:32.284(0)? (STDERR) at finishMaybe (_stream_writable.js:359:12)
W20150222-01:49:32.286(0)? (STDERR) at afterWrite (_stream_writable.js:279:5)
W20150222-01:49:32.286(0)? (STDERR) at onwrite (_stream_writable.js:269:7)
W20150222-01:49:32.286(0)? (STDERR) at WritableState.onwrite (_stream_writable.js:96:5)