In the WordPress database, you find there's a table called wp_options inside that table is an option called active_plugins . You can see it by typing: mysql> describe wp_options; This will show the following structure: +--------------+-----------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +--------------+-----------------+------+-----+---------+----------------+ | option_id | bigint unsigned | NO | PRI | NULL | auto_increment | | option_name | varchar(191) | NO | UNI | | | | option_value | longtext | NO | | NULL | | | autoload | varchar(20) | NO | MUL | yes | | +--------------+-----------------+------+-----+---------+----------------+ The relevant option is called active_plugins , so to see its content, type: mysql> select * from wp_options where option_name = "active_plugins"; This will retu
Turn debug mode on edit your wp-config.php file and find define('WP_DEBUG', false); change to define('WP_DEBUG', true); General causes of bugs 1. Dodgy plugins/templates. Remove them all and add them back one at a time. Same for themes 2. Config errors. Replace the config.php file with the template and reinstate it. Obviously copy/paste the login details for the database out before you do that, so when you recreate it, it asks for them again. 3. Code incompatibilities . You have some old code somewhere (e.g. an old php file) which was not upgraded and is now incompatible with the new php in the new issue of wordpress/plugin/template etc 4. Permission errors. chmod -R 755 /var/www/mysite chown -R www-data:www-data /var/www/mysite assuming your installation is located in /var/www/mysite. On a single-site server it will be /var/www/html "There has been a critical error on your website" = problem 3 above, usually.
If your wordpress site uses Elementor for layouts and suddenly the CSS stops working, look under Elementor -> Tools -> Regenerate CSS More detail here: https://elementor.com/help/custom-css-not-working/