Never tried APC but maybe a new release of vendor can fix this issue.

Try to test it: replace a new version with existing vendor\tedivm\stash\

Hello,

I encounter the same error on a brand new install of Elgg 3.1.3 (Ubuntu 18.04, PHP 7.2, nginx) :

Fatal error: APCuIterator::__construct(): Could not compile regular expression: [410dddb3a669b6e51a8398f10329061f::410dddb3a669b6e51a8398f10329061f::sp::stash_default::dic::di\definition\logger::*] in /Datastore/www/php72/esope_3.1/vendor/tedivm/stash/src/Stash/Driver/Apc.php on line 124

The error appeared after upgrading from a brand new 3.1.2 install (which broke because of the DB bug corrected in 3.1.3), from zip packaged version.

I also read https://elgg.org/discussion/view/2740445/cli-composer-install-issue and particularly https://github.com/Elgg/Elgg/issues/12289 and made some tests with various Stash versions (original packaged tedivm Stash version (0.14), but also with latest version 0.15.1).

It also works if i comment line 123 in Stash.php, but that is not a sustainable option... i still can't figure what's happening?

Any other feedbacks or information on this ?