无法在Alamofire 4.0中使用类型'（String，withName：String）'的参数列表调用'append'

I'm using Alamofire 4.0 to upload video to server after select or record it through device/camera but when I'm trying to call upload function with append , this error appeared to me in all append statement , what is the wrong in my code.I'm using Alamofire 4.0 to upload video to serv