"Internal Server Error - The server was unable to complete your request"

OS CentOS Linux release 7.9.2009
PLesk Obsidian version 18.0.34
php 7.4

Hello to the whole community, my first post.
I installed NextCloud via the php file following the guide, when I tried to log in the system gave me this error:

The server was unable to complete your request.
If this happens again, please send the following technical details to the server administrator.
Further details are available in the server log.

I asked to the server support they wrote me that:
401 errors emerge from the plesk log errors (errors that usually occur during authentication). Surely it can depend on htaccess.

here the logs:
500 - GET /index.php/apps/dashboard/ HTTP/1.0
500 - GET /index.php/js/activity/activity-sidebar.js
412 - GET /index.php/apps/recommendations/api/recommendations/always HTTP/1.0
500 - GET /index.php/apps/dashboard/undefined/img/notifications.svg
500 - GET /index.php/apps/dashboard/undefined/js/firstrunwizard-main.js
500 - GET /index.php/apps/dashboard/undefined/img/notifications-new.svg
404 - GET /ocs/v2.php/apps/notifications/api/v2/notifications HTTP/1.0

I hope someone’s help, thanks.