Circular reference detected for service "plugin.manager.block"

Ibrahim Tameme → made their first commit to this issue’s fork.

I have a same problem.
drupal 10.2.3
Ultimenu 2.10
Thanks to @Ibrahim-Tameme, based on your Merge request I created a patch application in ultimenu 2.10 version

Thank you.

I tried to reproduce it based on the OP instructions, but I couldn't, yet.

Also I don't understand why many unrelated services were removed and changed in the patch?

I couldn't reproduce it with D9, symfony_mailer:1.3.2, yet.

However based on the reported error, I only changed the offending service plugin.manager.block.
I could not put your patch in as I don't understand your other services removal.

Let me know my patch fix this issue? If not, please provide a consistent reproduction in D9.

I could reproduce it at D10, but not D9.

This will do for now till further investigation since it is only seen at D10, but not D9.

Committed. Thank you for contribution and patience!

Sorry, my patch #6 above replaced one less blockManager variable.
I create a new patch

Automatically closed - issue fixed for 2 weeks with no activity.

In Drupal 10.3.1 same problem exists.
I created a patch to fixed it.