Here are more details about the error,copied from the mail “Your Site is Experiencing a Technical Issue”:
When seeking help with this issue, you may be asked for some of the following information:
WordPress version 5.9.3
Current theme: Twenty Fourteen (version 3.4)
Current plugin: Widget Content Blocks (version 2.3.9)
PHP version 8.0.19
Error Details
=============
An error of type E_ERROR was caused in line 15 of the file /var/www/wp-content/plugins/wysiwyg-widgets/includes/plugin.php. Error message: Uncaught Error: Failed opening required ‘/var/www/wp-content/plugins/wysiwyg-widgets/includes/class-widget.php’ (include_path=’.:’) in /var/www/wp-content/plugins/wysiwyg-widgets/includes/plugin.php:15
Stack trace:
#0 /var/www/wp-includes/class-wp-hook.php(307): wywi_register_widget(”)
#1 /var/www/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters(NULL, Array)
#2 /var/www/wp-includes/plugin.php(474): WP_Hook->do_action(Array)
#3 /var/www/wp-includes/widgets.php(1854): do_action(‘widgets_init’)
#4 /var/www/wp-includes/class-wp-hook.php(307): wp_widgets_init(”)
#5 /var/www/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters(NULL, Array)
#6 /var/www/wp-includes/plugin.php(474): WP_Hook->do_action(Array)
#7 /var/www/wp-settings.php(587): do_action(‘init’)
#8 /var/www/wp-config.php(132): require_once(‘/var/www/wp-set…’)
#9 /var/www/wp-load.php(50): require_once(‘/var/www/wp-con…’)
#10 /var/www/wp-admin/admin.php(34): require_once(‘/var/www/wp-loa…’)
#11 /var/www/wp-admin/plugins.php(10): require_once(‘/var/www/wp-adm…’)
#12 {main}
thrown`
