I am seeing this in the admin panel logs (which can only be accessed after restarting php), as well as a visible error message:
What I am not so sure of is why this would come up with no changes made on my end, this is running php 7.2.8 and IPB 4.3.5 (admittedly out of date because the theme I have will break if I update). I need to update my PHP image however some modules have changed from php7.2 to php7.4.