Fatal error: Call to undefined function apply_filters() in /public_html/wp-includes/load.php on line 317

Question

I tried to update my wordpress installation using auto update feature. After update the entire site is down. Checking the log file I have this error:
Fatal error:

Answer 1

This problem was caused by the wp-settings.php. Due to permissions trouble this file was not updated while using auto-update. Replacing this file with the latest wp-settings.php solved the trouble.

Answer 2

i just add and use this line to my plugin file

require_once( dirname(FILE) . '/../../../../wp-includes/plugin.php');