No visualizo paginas para edición en dashboard

Hola @mpcdigital .. mira me sale estos errores por medio del error_log de diferentes archivos

06-Jul-2022 06:12:29 UTC] PHP Warning:  Use of undefined constant ABSPATH - assumed 'ABSPATH' (this will throw an Error in a future version of PHP) in /home/artifexl/public_html/wp-includes/class-wp-http.php on line 11
[06-Jul-2022 06:12:29 UTC] PHP Warning:  Use of undefined constant WPINC - assumed 'WPINC' (this will throw an Error in a future version of PHP) in /home/artifexl/public_html/wp-includes/class-wp-http.php on line 11
[06-Jul-2022 06:12:29 UTC] PHP Warning:  require(ABSPATHWPINC/class-requests.php): failed to open stream: No such file or directory in /home/artifexl/public_html/wp-includes/class-wp-http.php on line 11
[06-Jul-2022 06:12:29 UTC] PHP Warning:  require(ABSPATHWPINC/class-requests.php): failed to open stream: No such file or directory in /home/artifexl/public_html/wp-includes/class-wp-http.php on line 11
[06-Jul-2022 06:12:29 UTC] PHP Fatal error:  require(): Failed opening required 'ABSPATHWPINC/class-requests.php' (include_path='.:/opt/alt/php74/usr/share/pear') in /home/artifexl/public_html/wp-includes/class-wp-http.php on line 11
[06-Jul-2022 06:13:30 UTC] PHP Fatal error:  Uncaught Error: Call to undefined function get_the_block_template_html() in /home/artifexl/public_html/wp-includes/template-canvas.php:12
Stack trace:
#0 {main}
  thrown in /home/artifexl/public_html/wp-includes/template-canvas.php on line 12

[06-Jul-2022 06:16:17 UTC] PHP Fatal error: Uncaught Error: Class ‘WP_Widget’ not found in /home/artifexl/public_html/wp-includes/widgets/class-wp-widget-block.php:17
Stack trace:
#0 {main}
thrown in /home/artifexl/public_html/wp-includes/widgets/class-wp-widget-block.php on line 17

@mpcdigital agradezco mucho si me puedes orientar el como solucionar esos inconvenientes porq no se mucho del tema …

Muchas gracias

@mpcdigital buenas tardes … sabes q ya le cambie la version de php a una anterior, pero aun nada..

aparte me sale esto en el site heatlh

4 recommended improvements
You should remove inactive plugins Security
Your site is running an older version of PHP (7.3.33), which should be updated Performance
301 .htaccess redirect is not enabled. Security
Not all recommended security headers are installed Security

Your website does not send all recommended security headers.

    Upgrade Insecure Requests
    X-XSS protection
    X-Content Type Options
    Referrer-Policy
    X-Frame-Options
    Permissions-Policy
    HTTP Strict Transport Security

Learn more about security headers

me podrias indicar a q se refiere, por favor te lo agradezco muchisisimo