Hi
I did the check under 3.10.1 and everything went well because the extensions and normally the templating t4 bss5 was compatible.
All extensions work with cassiopa but not with your theme:
So I reinstalled the t4_bss5 template without any problem but I have an error message when uploading the file in the backoffice (I took it a 2nd time on your site)
Regards
MySQL server has gone away
Joomla\Database\Exception\ PrepareStatementFailureException
in /home/.../public_html/libraries/vendor/joomla/database/src/Mysqli/MysqliStatement.php (line 141)
in /home/.../public_html/libraries/vendor/joomla/database/src/Mysqli/MysqliDriver.php -> __construct (line 1048)
in /home/.../public_html/libraries/vendor/joomla/database/src/DatabaseDriver.php -> prepareStatement (line 1900)
DatabaseDriver->setQuery(object(MysqliQuery)) in /home/.../public_html/libraries/src/Helper/ModuleHelper.php (line 490)
}
$query->order($db->quoteName(['m.position', 'm.ordering']));
// Set the query
$db->setQuery($query);