@mahagr can you please take a look at this?

I think this is again related to opcache default settings, where it checks the changes in the classes every 2 seconds. The easiest way to fix this kind of issue is to handle updates separately, using a separate entry point to do it.

Hmm. The autoloader that breaks in this instance comes from the new Admin version. This means that the issue seems to be slightly different from the previous issue we saw; PHP may be loading the old version of the class inside /vendor/composer/autoload_real.php file after loading the updated vendor/autolaod.php file.

Hmm.. I just looked into PHP docs and it looks like opcache_reset() works only once per script and should be only called in the end of the script.

BTW, i've noticed this a few times in recent updates. I just run update a second time and it finishes the rest of the plugins. So annoying and frustrating that an error displays and means it takes 2 tries, but not breaking anything.

Since posting this issue I have done a lot more updates and had no problems at all. Everything has gone smoothly.