Resolved Error Apache bugs Debian 9.13‬ - Plesk Obsidian 18.0.21

[kameleon1er]

Hi there, I took a fresh OVH VPS serveur with default configuration : Debian 8 . I upgraded to Debian9 and in the other hand, upgrade Plesk too.
I activate a new domain in Plesk but the system give me an error ;

Unable to configure the web server: Execution failed. Command: httpdmng Arguments: Array ( [0] => --reconfigure-all ) Details: Error occured while sending feedback. HTTP code returned: 429 Execution failed. Command: httpdmng Arguments: Array ( [0] => --reconfigure-domains [1] => democrasite.com ) Details: [2020-08-08 00:30:19.646] ERR [util_exec] proc_close() failed ['/opt/psa/admin/bin/apache_control_adapter' '--restart' '--restart-interval' '0' '--http-port' '7080' '--https-port' '7081' '--graceful'] with exit code [255] [2020-08-08 00:30:20.018] ERR [panel] Apache config (15968464920.99087000) generation failed: Template_Exception: Can not restart web server: Apache is down, start it instead of graceful Apache is down, start it instead of graceful file: /opt/psa/admin/plib/Service/Driver/Web/Server/Apache.php line: 111 code: 0 Can not restart web server: Apache is down, start it instead of graceful Apache is down, start it instead of graceful

If I try to let Plesk fix it, it can't :

-rw------- 1 root www-data 2466 Aug 8 00:39 /etc/apache2/plesk.conf.d/webmails/democrasite.com_webmail.conf

[B]Error:[/B] Can not reconfigure web server configurations: Unable to execute httpdmng: [2020-08-08 01:00:36.095] ERR [util_exec] proc_close() failed ['/opt/psa/admin/bin/apache_control_adapter' '--restart' '--restart-interval' '0' '--http-port' '7080' '--https-port' '7081' '--graceful'] with exit code [255] [2020-08-08 01:00:36.462] ERR [panel] Apache config (15968483090.39151800) generation failed: Template_Exception: Can not restart web server: Apache is down, start it instead of graceful Apache is down, start it instead of graceful file: /opt/psa/admin/plib/Service/Driver/Web/Server/Apache.php line: 111 code: 0 Can not restart web server: Apache is down, start it instead of graceful Apache is down, start it instead of graceful

With my terminal I can see Apache is up. Is this message just a warning or serious problem, and how to fix it ?

Thanks