Call to undefined function: mysqli_connect(). Please install the MySQL Connector for

[wvmarle]

I'm running Debian Buster, and recently found out PayPal isn't working for missing curl. I tried to install php-curl module, but no improvement. It still complained about the missing curl.

Next I found out there were still some php5 packages, and ZenCart was using php5 instead if php7.3 which I also had installed. In fact php5-curl was installed all the time, as was php7.3-curl. I figured that's maybe causing a conflict, so I removed everything from php5 which is outdated anyway, hoping for some improvement, but no: now it says "Call to undefined function: mysqli_connect(). Please install the MySQL Connector for PHP", and the whole zencart stopped working.

The module php-mysqli was installed already. I tried removing and re-installing it, but no improvement.

My ZenCart was 1.5.5a, saying it's the latest version, but I found otu there's a newer version available that's written for php7.3. Great, I'd love to install this, trying to follow the instructions, but again it's stuck on claiming it misses the mysqli module, which is installed!

$ sudo apt-get install php-mysqli
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Note, selecting 'php7.3-mysql' instead of 'php-mysqli'
php7.3-mysql is already the newest version (7.3.14-1~deb10u1).

As a result not only have I lost PayPal payment method, the whole web site is currently down. What's going on??

[carlwhat]

rest assured, it is not active for the version of php your website is currently running.

can you create a phpinfo page? in your root directory create a file called info.php and put in:

<?php
phpinfo();

there you can see the version of php you are running and that mysqli is not running.

have you tried restarting apache?

sudo service apache2 restart