Http GET : Possibly unhandled rejection

I am new with angular. I want to get the data from an action name (MVC) using http.

In the console I got a GET line, then the following error occurs : "Possibly unhandled rejection: ": {"data":"\r\n\r\n \r\n "

My code in the html view file :

       [HttpGet]
    public ActionResult OPCVMLoad()
    {
        OPCVM opcvm1 = new OPCVM();
        opcvm1.OPCVMcode = 1;
        opcvm1.OPCVMname = "Bernardin";
        return Json(opcvm1, JsonRequestBehavior.AllowGet);
    }



<script>

    var myApp = angular.module("myApp", []);
    myApp.controller('OPCVMViewModel', ['$scope', '$http', function ($scope, $http) {

        $scope.OPCVM = {
            "OPCVMcode": "",
            "OPCVMname": ""
        };
        $scope.OPCVMs = {};

        $scope.TestClick = function TestClick() {
            alert("test clic");
        };

        $scope.GetAllData = function GetAllData() {
            alert("break point in function GetAllData");
            $http.get("GrilleFast/OPCVMLoad")
                .then(function (response)
                {
                    $scope.OPCVM  = response.data; 
                }) 

        };

    }]);

</script>


<div ng-controller="OPCVMViewModel">
    <input name="BtnAddNew" type="button" value="Load all OPCVM" ng-click="GetAllData()"  />
    {{OPCVM.OPCVMcode}}        <br />
    {{OPCVM.OPCVMname}}




</div>

My code in the .cs file (action MVC)

        [HttpGet]
    public ActionResult OPCVMLoad()
    {
        OPCVM opcvm1 = new OPCVM();
        opcvm1.OPCVMcode = 1;
        opcvm1.OPCVMname = "Bernardin";
        return Json(opcvm1, JsonRequestBehavior.AllowGet);
    }