I found a log under /var/www/vhosts... in a folder specifying the domain where the setup is accessed under, here is a message from the time of attempt:
[Wed Jan 27 15:03:47.003943 2021] [proxy_fcgi:error] [pid 41396] [client 89.0.20.209:53369] AH01071: Got error 'PHP message: PHP Fatal error: Uncaught PDOException: SQLSTATE[08S01]: Communication link failure: 1153 Got a packet bigger than 'max_allowed_packet' bytes in /var/www/vhosts/****/ilias.****.de/Services/Database/classes/PDO/class.ilPDOStatement.php:104\nStack trace:\n#0 /var/www/vhosts/****/ilias.****.de/Services/Database/classes/PDO/class.ilPDOStatement.php(104): PDOStatement->execute(Array)\n#1 /var/www/vhosts/****/ilias.****.de/Services/Database/classes/PDO/class.ilDBPdo.php(1407): ilPDOStatement->execute(Array)\n#2 /var/www/vhosts/****/ilias.****.de/setup/classes/class.ilDbSetup.php(173): ilDBPdo->execute(Object(ilPDOStatement))\n#3 /var/www/vhosts/****/ilias.****.de/setup/classes/class.ilDbSetup.php(191): ilDbSetup->readDumpUltraSmall()\n#4 /var/www/vhosts/****/ilias.****.de/setup/classes/class.ilSetup.php(239): ilDbSetup->instal...\n', referer: https://ilias.****.de/setup/setup.php?cmd=db&client_id=ILIASNH01&back=clientlist
[Wed Jan 27 15:03:47.003943 2021] [proxy_fcgi:error] [pid 41396] [client 89.0.20.209:53369] AH01071: Got error 'PHP message: PHP Fatal error: Uncaught PDOException: SQLSTATE[08S01]: Communication link failure: 1153 Got a packet bigger than 'max_allowed_packet' bytes in /var/www/vhosts/****/ilias.****.de/Services/Database/classes/PDO/class.ilPDOStatement.php:104\nStack trace:\n#0 /var/www/vhosts/****/ilias.****.de/Services/Database/classes/PDO/class.ilPDOStatement.php(104): PDOStatement->execute(Array)\n#1 /var/www/vhosts/****/ilias.****.de/Services/Database/classes/PDO/class.ilDBPdo.php(1407): ilPDOStatement->execute(Array)\n#2 /var/www/vhosts/****/ilias.****.de/setup/classes/class.ilDbSetup.php(173): ilDBPdo->execute(Object(ilPDOStatement))\n#3 /var/www/vhosts/****/ilias.****.de/setup/classes/class.ilDbSetup.php(191): ilDbSetup->readDumpUltraSmall()\n#4 /var/www/vhosts/****/ilias.****.de/setup/classes/class.ilSetup.php(239): ilDbSetup->instal...\n', referer: https://ilias.****.de/setup/setup.php?cmd=db&client_id=ILIASNH01&back=clientlist