wordpress critical error

1. Reset your plugins folder via FTP or the file manager provided in your host’s control panel. This method preserves plugin options but requires plugins be manually reactivated.

• Navigate to the wp-contents folder
• Rename the folder plugins in it to plugins.hold
• Login to your WordPress then go to Dashboard > Plugins yourdomain.com/wp-admin/plugins.php – this will disable any plugin that is “missing”, so all of them.
• Then, rename plugins.hold back to plugins and activate in Dashboard all the plugins except the one causing troubles

2. Use phpMyAdmin to deactivate all plugins.

• In the table wp_options, under the option_name column (field) find the active_plugins row
• Change the option_value field to: a:0:{}. This will deactivate all plugins.
• Then from Dashboard you need to reactivate all plugins, except the one causing you troubles

If that does not resolve the issue, access your server via SFTP or FTP, or a file manager in your hosting account’s control panel, navigate to /wp-content/themes/ and rename the directory of your currently active theme. This will force the default theme to activate and hopefully rule-out a theme-specific issue (theme functions can interfere like plugins).