Have a Perfect Stretch apache2, mariadb setup. In researching a LE issue, I found a few of these earlier in the day PHP Warning: mysqli_query() expect parameter 1 to me mysqli, null given in /use/local/ispconfig/server/lib/classes/db_mysql.inc.php Looking at previous posts suggested to look at mysql passwords, but those fields are "" in db_mysql.inc.php...just like it is in my other servers. I then found that /etc/php/7.0/apache2/php.ini has ;extension=php_mysqli.dll commented out and there is no line for php_mysqli.so that I would expect. Should I uncomment it or is that for windows only? Any thoughts on the actual mysqli_query() problem?