flex - Adobe AIR file upload response data in complete handler is null while fiddler(web debugger) shows that json is returned as response -

when uploading file adobe air backbone server, response returned not anyway accessible when using file.upload(request) function, while can see json response in fiddler(web debugger , in task manager), working fine when using urlloader.load() instead of file.upload()

var url = "api url of backbone server "; request = null; file = null;  request = new air.urlrequest(url); request.usecache = false;  var authorization = new air.urlrequestheader("authorization", "bearer "+accesstoken); var contenttype = new air.urlrequestheader("content-type", "multipart/form-data; boundary=" + boundary); var accept = new air.urlrequestheader("accept", "application/json;charset=utf-8");  request.requestheaders.push(authorization); request.requestheaders.push(contenttype); request.requestheaders.push(accept);      file = new air.file(path); pathnative = file.nativepath; var directory = getdirectoryfrompath(pathnative);  params = new air.urlvariables(); params.parent_id = directory.directory_id; params.name = file.name; request.data = params; request.method = air.urlrequestmethod.post; request.contenttype = 'multipart/form-data, boundary='+boundary;  var file = new air.file(path); file.upload(request); file.addeventlistener(air.event.complete, function(e){      air.introspector.console.log(file);     air.introspector.console.log(e);     air.introspector.console.log(e.target.data); }); 

this console complete event can see returned data null. see console while in fiddler shows json returned. see fiddler

seems it's known issue on ios? trying ios?

https://forums.adobe.com/thread/1720117?start=0&tstart=0