Why upload file not work with this code?

I am new with ionic, and I want to upload picture. thus I use “ng-file-upload” to upload my picture.
but the code not work only if I remove ion-content my template is:

<ion-view view-title="IQ Marketplace" ng-controller="SellCtrl">
<ion-content class="padding" >
  <form   ng-submit="submitAds()" name="form" novalidate>
    <label class="item item-input">
      <span class="input-label">Picture</span>
  <input type="file" ngf-select ng-model="file" name="file" ngf-pattern="'image/*'"  accept="image/*" >
    </label>
<input type="submit" class="button button-block button-positive" value="Save" ng-disabled="form.$invalid">
</form>
</ion-content>
</ion-view>

And my controller is:
.controller(‘SellCtrl’, function($scope,Upload) {

                      $scope.submitAds = function() {
                        console.log("ayman "+ $scope.file)
                          $scope.upload($scope.file);
                      };
                       $scope.upload = function (file) {
                          Upload.upload({
                              url: 'http://localhost/IQM/public/ads',
                              data: {file: file, 'username': $scope.test}
                          }).then(function (resp) {
                              console.log('Success ' + resp.config.data.file.name + 'uploaded. Response: ' + resp.data);
                          }, function (resp) {
                              console.log('Error status: ' + resp.status);
                          }, function (evt) {
                              var progressPercentage = parseInt(100.0 * evt.loaded / evt.total);
                              console.log('progress: ' + progressPercentage + '% ' + evt.config.data.file.name);
                          });
                      };
      });

This code give me this exception:
TypeError: Cannot read property ‘name’ of undefined
at controllers.js:84
at ionic.bundle.js:23476
at Scope.$eval (ionic.bundle.js:24673)
at Scope.$digest (ionic.bundle.js:24484)
at ionic.bundle.js:24712
at completeOutstandingRequest (ionic.bundle.js:14221)
at ionic.bundle.js:14493

But when I remove the “ion-content” the upload will successful.
What is the problem?