diff --git a/core/misc/progress.js b/core/misc/progress.js
index 2e3a878..c1f82a2 100644
--- a/core/misc/progress.js
+++ b/core/misc/progress.js
@@ -87,7 +87,9 @@ $.extend(Drupal.ProgressBar.prototype, {
           pb.timer = setTimeout(function () { pb.sendPing(); }, pb.delay);
         },
         error: function (xmlhttp) {
-          throw new Drupal.AjaxError(xmlhttp, pb.uri);
+          var e = new Drupal.AjaxError(xmlhttp, pb.uri);
+          pb.displayError(e.message);
+          throw e;
         }
       });
     }
