0 Cannot use object of type stdClass as array

when adding menu items: 0 Cannot use object of type stdClass as array

>> plugins/helix 3 Framework > DISABLE

wordpress site is briefly unavailable error

https://themify.me/blog/how-to-fix-maintenance-mode?mc_cid=c078ca3d05&mc_eid=1debbeaa26

Themler edit template not working, blank window

http://answers.themler.io/questions/181166/problem-with-edit-themler-theme

 When I click EDIT button it can not open but a see blank (white) window with nothing.

How to Fix the error after updating to Joomla 3.9

If you updated to the latest version and the following error appears when you try to launch Themler please follow the instruction below:

Fatal error: require_once(): Failed opening required '[...]/administrator/includes/toolbar.php' (include_path='.:/usr/lib/php7.2') in [...]/templates/[theme_name]/app/index.php on line 25

1. Open theme folder on the server: www/Joomla_directory/templates;
2. open /app folder;
3. open index.php for editing in any html or text editor;
4. find the line
   require_once JPATH_BASE . DS . 'includes' . DS . 'toolbar.php';
   and replace it with the following line:
   $prefix = version_compare(JVERSION, '3.9', '>=') ? 'sub' : '';
require_once JPATH_BASE . DS . 'includes' . DS . $prefix . 'toolbar.php';;
5. open /app/start folder;
6. open data.php file for editing and follow step 4;
7. open manifest.php file for editing and follow step 4;
8. start Themler.