Mysqli error in error.log

Hi all,
I am running openemr 7.0.2 on a xampp installation with php 8.2.12/Apache 2.4.58/MariaDB 10.4.32.
Recently the system collapsed when several users saved patient data simultaneously. The error.log shows for this timeframe multiple errors from this category:

PHP Fatal error: Uncaught TypeError: mysqli_query(): Argument #1 ($mysql) must be of type mysqli, bool given in C:\xampp2\htdocs\openemr\vendor\adodb\adodb-php\drivers\adodb-mysqli.inc.php:1370\nStack trace:\n#0 C:\xampp2\htdocs\openemr\vendor\adodb\adodb-php\drivers\adodb-mysqli.inc.php(1370): mysqli_query(false, 'SET NAMES ‘utf8…’, 0)\n#1 C:\xampp2\htdocs\openemr\vendor\adodb\adodb-php\adodb.inc.php(1613): ADODB_mysqli->_query('SET NAMES ‘utf8…’, false)\n#2 C:\xampp2\htdocs\openemr\vendor\adodb\adodb-php\drivers\adodb-mysqli.inc.php(1113): ADOConnection->_Execute('SET NAMES ‘utf8…’)\n#3 C:\xampp2\htdocs\openemr\library\ADODB_mysqli_log.php(60): ADODB_mysqli->execute('SET NAMES ‘utf8…’, false)\n#4 C:\xampp2\htdocs\openemr\library\sql.inc.php(66): ADODB_mysqli_log->ExecuteNoLog('SET NAMES ‘utf8…’)\n#5 C:\xampp2\htdocs\openemr\interface\globals.php(301): require_once(‘C:\\xampp2\\htdoc…’)\n#6 C:\xampp2\htdocs\openemr\interface\main\main_screen.php(19): require_once(‘C:\\xampp2\\htdoc…’)\n#7 {main}\n thrown in C:\xampp2\htdocs\openemr\vendor\adodb\adodb-php\drivers\adodb-mysqli.inc.php on line 1370

Can this be the reason for the system crash? How can I fix it?

Thank you!
F.M.