I haven’t updated WordPress for a while and I was getting the what is know as White Screen Of Death. Basically once I login on the admin panel, all the screens are white and I cannot click or do anything.

In the source of the pages, there is an error message like:

Fatal error: Access to undeclared static property: WP_Screen::$this in wp-admin/includes/screen.php on line 706

To fix this, you will need to access the files on the server, and modify the following file in your favorite text editor:

your-site/wp-admin/includes/screen.php

Go to line 706 and modify the line from:

<?php echo self::$this->_help_sidebar; ?>

to

<?php echo $this->_help_sidebar; ?>

In summary, remove the ‘self::‘ part.

Save it and re-login/refresh your WordPress admin panel.