So no need to worry only small changes need to do I have recently faced this issue It appears that when update the PHP version, you May have forgot to enable the php.ini file
WordPress is trying to include the file functions.php which should be located in /home/mysite/wp-includes/ but the file is not found. Please check if the file exists, otherwise download it from the WordPress website and add it to your WordPress website. If that does not work, try to reinstall WordPress (don’t forget to backup your data).
Try turning on WP Debug. If this is happening due to a PHP error, you will be able to see what’s going on and fix the error.
- Turn on debugging log in Wp-config.php
- Disable plugins by adding a 1 just before every plugin folder
- Repair all tables from your MySql database (repair is a mysql feature. Repair command
- does not hurt)
- Check htaccess for bad redirects
- Check folders/files permissions (755,644)
- Add the following in wp-config.php