After upgrading a stable Joomla 3.10.11 website from PHP 7.4 to PHP 8.0, the following error is displayed on the front end and back end of the website:
Warning: session_start(): Failed to read session data: user (path: /tmp) in /home/xxxxxxxx/public_html/libraries/joomla/session/handler/native.php on line 260
I have already checked that the appropriate PHP extensions (such as
mysqli) are enabled in cPanel -> Select PHP Version -> Extensions for PHP 8.0.
I am also seeing the same issue on some of my Joomla 4 websites.