--- a/browser/base/content/urlbarBindings.xml
+++ b/browser/base/content/urlbarBindings.xml
@@ -1263,16 +1263,19 @@
       <handler event="command"><![CDATA[
         let target = event.originalTarget;
         if (target.classList.contains("addengine-item")) {
           // On success, hide and reshow the panel to show the new engine.
           let installCallback = {
             onSuccess: function(engine) {
               event.target.hidePopup();
               BrowserSearch.searchBar.openSuggestionsPanel();
+            },
+            onError: function(errorCode) {
+              Components.utils.reportError("Error adding search engine: " + errorCode);
             }
           }
           Services.search.addEngine(target.getAttribute("uri"),
                                     Ci.nsISearchEngine.DATA_XML,
                                     target.getAttribute("image"), false,
                                     installCallback);
         }
       ]]></handler>