HI,

As you know we are not Xampp support, and that seems to be problem with software settings. This error typically occurs when the CMS cannot receive a response from the MySQL server. One primary reason for this error is a timeout. This can happen if a query takes too long to execute, or if there is a period of inactivity.

Modify Configuration File: Edit the MySQL configuration file (my.cnf or my.ini) to adjust settings like wait_timeout and max_allowed_packet:

[mysqld]
wait_timeout = 28800
interactive_timeout = 28800
max_allowed_packet = 64M

After making changes to the configuration file, restart the MySQL service to apply the changes.

1. Are you able to install clean/raw Joomla 4.x (joomla.org) first? Try.
2. Later read tips from:

• https://kinsta.com/knowledgebase/mysql-server-has-gone-away/
• https://dbserv.com/blog/mysql-server-has-gone-away
• https://marketsplash.com/mysql-server-has-gone-away/

and you will know what to check & change. More in XAMPP documenation.