fix

assets/core/core.js

@@ -824,12 +824,16 @@ kit.config = kit.config || {};
      * @param {function} callback
      * @memberOf kit
      */
+
     PluginManager.prototype.ready = function(deps, callback = undefined) {
         var self = this;
         if(typeof deps === 'function') {
             callback = deps;
             deps = [];
         }
+        if(typeof callback !== 'function') {
+            callback = function (){};
+        }
         self.__ready(self.exec, [deps, callback], self);
     };
     PluginManager.prototype.__ready = function(fn, args = [], context = window) {