Upload onUploadComplete event not Triggering

I can upload a file on the server, but the onUploadComplete event does not trigger

http://webix.com/snippet/6d8d9f7d

As far as I can see, it works

http://webix.com/snippet/ae67b51c

Please note the following requirements. Regardless of the language, the script must contain:

  • the desired destination for file uploading;
  • script response in form of a JS string - {“status”:“server”} for success, {“status”:“error”} for failure.

Thank you setting the server response was my problem.