Error: Class "Doctrine\Common\Collections\ArrayCollection" not found

What is your Drupal version?
Did you install Address via Composer or Ludwig?

We're running Drupal 10.1.5, and we installed Address via Composer.

Hm, we require doctrine/collections in the composer.json for commerceguys/addressing, so it should be impossible for the package to be missing. Furthermore, ArrayCollection is present in every version of doctrine/collections.

If you can check what versions of commerceguys/addressing and doctrine/collections Composer has installed, that might help us with further debugging.

Of course:
commerceguys/addressing:1.4.2
doctrine/collections:2.1.4

I apologize for the late response.

You specified that you're using Address 2.0.x-dev which requires commerceguys/addressing v2.0.0 or newer, but your site has v1.4.2 installed. That is odd. Still, both addressing versions do allow doctrine/collections v2.1.4 to be used.

Looking at doctrine/collections v2.1.4, I see an ArrayCollection class included: https://github.com/doctrine/collections/blob/2.1.4/src/ArrayCollection.php

So this can only be some kind of autoloading bug.

...oy. There's the problem. I chose the wrong version for the issue. We're using drupal/address 1.12.0.

I'm sorry...

Thanks, updating the affected version.

However, my point from #6 still stands, the doctrine version looks fine and I can't explain the error, other than possibly relating it to autoloading.

I can only advise trying to require doctrine/colections ~1.6 or ~2.0 to see if an older branch maybe doesn't exhibit the same problem.

I ran into the same issue during a D8 -> D10 upgrade when I updated address to ^2. I'm guessing it's a weird autoload issue because the directory structure of doctrine/collections changes between v1 and v2.

I tried running composer dump-autoload an composer cc but neither worked. I ended up needing to explicitly require an older version of doctrine/collections in my top-level composer.json (composer require 'doctrine/collections:^1.2') to get things working again.

I ran into the same issue - unable to view any orders. We can view the orders list page, but when we try to view an order we're getting this error. I had to downgrade to doctrine/collections 1.8.0 and now it's working.