ASP.NET WEBAPI file upload, issues with IE9

I have created a file upload method using ASP.NET WEBAPI, below the code: ``` [DataContract] public class FileDesc { [DataMember] public string name { get; set; } [DataMember] public string url { get; set; } [DataMember] public long size { get; set; } [DataMember] public string UniqueFileName { get; set; } [DataMember] public int id { get; set; } [DataMember] public DateTime modifiedon { get; set; } [DataMember] public string description { get; set; } public FileDesc(string rootUrl, FileInfo f,int pId, string aFileName) { id = pId; name = aFileName; UniqueFileName = f.Name; url = rootUrl + "/Files/" + f.Name; size = f.Length / 1024; modifiedon = f.LastWriteTime; description = aFileName; } } public class CustomMultipartFormDataStreamProvider : MultipartFormDataStreamProvider { //string uniqueFileName = string.Empty; public string UniqueFileName { get; set; } public string ActualFileName { get; set; } public int TaskID { get; set; } private int UserID { get; set; } public CustomMultipartFormDataStreamProvider(string path, int ptaskID, int pUserID) : base(path) { TaskID = ptaskID; UserID = pUserID; } public override string GetLocalFileName(System.Net.Http.Headers.HttpContentHeaders headers) { var name = !string.IsNullOrWhiteSpace(headers.ContentDisposition.FileName) ? headers.ContentDisposition.FileName : "NoName"; ActualFileName = name.Replace("\"", string.Empty); ActualFileName = Path.GetFileName(ActualFileName); UniqueFileName = Guid.NewGuid().ToString() + Path.GetExtension(ActualFileName); int id = SaveFileInfoIntoDatabase(ActualFileName, TaskID, UniqueFileName, UserID); headers.Add("ActualFileName", ActualFileName); headers.Add("id", id.ToString()); return UniqueFileName; } } [Authorize] public class FileUploadController : ApiController { private string StorageRoot { get { return Path.Combine(System.Web.HttpContext.Current.Server.MapPath("~/Files/")); } //Path should! always end with '/' } public Task<IEnumerable<FileDesc>> Post(int id) { string folderName = "Files"; string PATH = HttpContext.Current.Server.MapPath("~/" + folderName); string rootUrl = Request.RequestUri.AbsoluteUri.Replace(Request.RequestUri.AbsolutePath, String.Empty); HttpContext.Current.Response.BufferOutput = true; HttpContext.Current.Response.Buffer = true; HttpContext.Current.Response.ContentType = "text/html"; if (Request.Content.IsMimeMultipartContent()) { var streamProvider = new CustomMultipartFormDataStreamProvider(PATH, id, BEL_PMS.Utilities.FormsAuthenticationUtil.GetCurrentUserID); var task = Request.Content.ReadAsMultipartAsync(streamProvider).ContinueWith<IEnumerable<FileDesc>>(t => { if (t.IsFaulted || t.IsCanceled) { throw new HttpResponseException(HttpStatusCode.InternalServerError); } var fileInfo = streamProvider.FileData.Select(i => { var info = new FileInfo(i.LocalFileName); int FileID = Convert.ToInt32((from h in i.Headers where h.Key =="id" select h.Value.First()).FirstOrDefault()); string ActualFileName = (from h in i.Headers where h.Key =="ActualFileName" select h.Value.First()).FirstOrDefault(); return new FileDesc(rootUrl, info, FileID, ActualFileName); }); return fileInfo; }); //return new HttpResponseMessage { StatusCode = System.Net.HttpStatusCode.OK, Content = task}; return task; } else { throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotAcceptable, "This request is not properly formatted")); } } } ``` and uploading files via Ajax using jquery.form.js plugin, below is the code: ``` $('#frmmultiupload').ajaxForm({ success: OnUploadedSuccessfully, error: function (x, y) { mesg('Error occured while file upload! Please make sure that total file size is less than 4 MB and try again.', 'error', 'File upload failed.'); } }); ``` everything works file but it is creating problem in IE9 IE says "Do you want to open or save from local host?" Below is the network trace: I found some hint here not don't know how to convert `Task<IEnumerable<FileDesc>>` to `Task<HttpResponseMessage>`. I have specified timeout of 30 sec in ajaxSetup, so after 30 sec it is generating error.