1.0.9.3 PHP 8.2
I know this is a tall order but in my admin error log file I am getting one of these for every page load in admin. Shop side is unaffected.
I'm going to say that it looks like something is loaded twice in php.ini
Could you contact your host and see if they can take a look at their server setup.
Although it is strange that this happens in the admin side yet not in the shop side.
I am not here to build for you.
I am here to build with you. Let's help each other.
Another possible cause is that the MySQL server needs rebooted/restarted. That gives identical symptoms to the duplicate entries in php.ini but is more likely to happen just to the admin.
It's one of those, "I don't actually know what was wrong, but restarting fixed it" problems. Not a definite answer, but worth trying.
Alternately, if you have the ability to set php.ini values on a per directory basis, you might check if you have mysqli set in both admin and catalog, duplicating it.
I think my hosts implementation of PHP 8.2 is flawed as I had to prompt them to activate "intl" even though it was ticked in cpanel.
If I roll back to 8.0 or 8.1 the errors go away so I will stick with 8.1 until my hosts get their act together.