Merge pull request #3369 from magento-obsessive-owls/owls-ce

[Owls] PageBuilder Bug Fixes with core changes

Author: cpartica

lib/web/mage/adminhtml/wysiwyg/tiny_mce/tinymce4Adapter.js

@@ -117,7 +117,7 @@ define([
             jQuery.when.apply(jQuery, deferreds).done(function () {
                 tinyMCE4.init(settings);
                 this.getPluginButtons().hide();
-                this.eventBus.attachEventHandler('open_browser_callback', this.openFileBrowser);
+                this.eventBus.attachEventHandler('open_browser_callback', tinyMceEditors.get(self.id).openFileBrowser);
             }.bind(this));
         },
 
@@ -129,7 +129,7 @@ define([
         removeEvents: function (wysiwygId) {
             var editor;
 
-            if (typeof tinyMceEditors !== 'undefined') {
+            if (typeof tinyMceEditors !== 'undefined' && tinyMceEditors.get(wysiwygId)) {
                 editor = tinyMceEditors.get(wysiwygId);
                 varienGlobalEvents.removeEventHandler('tinymceChange', editor.onChangeContent);
             }