We recently had someone come to us asking for help with an older wordpress install (3.1.1) that had some problems. They could login to the admin area, but the main content area screen was blank.
The admin area displayed this error in the source:
Fatal error: Access to undeclared static property: WP_Screen::$this in blog/wp-admin/includes/screen.php on line 706
- Open file wp-admin/includes/screen.php in whatever editor you use.
- Scroll to line 706 find the following PHP statement:
<?php echo self::$this->_help_sidebar; ?>
- Replace the old statement, with this new statement:
<?php echo $this->_help_sidebar; ?>
- Save your changes.