JQuery Auto complete and webapi 2

I am using WebApi to try and get json arry to my autocomplete jquery in my website,

I simpley need to trun a List into a auto complete object so i can show my clients a list of templates,

This is my Javascript Code -

<script>
    var availableTags;
    $.get(
  "http://localhost:59040/api/Email/GetTemplates",
  { 'FirstName': "what she say", '': "sayhey" }, // put your parameters here
  function (responseText) {
     availableTags = responseText;
     console.log(availableTags);
     DoIt();

  }
  );
  function DoIt(){

$(function () {
        var ava = availableTags;
        if (availableTags){
        console.log("Its done")
        $("#TemplatesAuto").autocomplete({
            source: availableTags
      });
      }
      else {
      console.log("Not");
      }
    });
};


</script>

And my webapi Controller Code :

  //Get templates
        [HttpGet]//omUrl/{url?}
        [Route(@"~/api/Email/GetTemplates")]
        [EnableCors(origins: "*", headers: "*", methods: "*")]
        public string GetTemplates()
        {
            List<string> Names = new List<string>();
            Names.Add("Check");
            Names.Add("Check");
             JavaScriptSerializer serializer = new JavaScriptSerializer();
             return serializer.Serialize(Names);   
        }

Seems normal, works. BUT, when i try to write something in my autocomplete input, i get this error:

GET http://localhost:54662/Check/[%22Check%22,%22Check%22]?term=c 404 (Not Found)

I am getting crazy out here, looking for hours for the answer before coming here,

Please help.

Thanks alot, Good day :)