Attempted to load class "ContainerAwareEventDispatcher"?

Question

symfony

[email protected]:/srv/test$ console doctrine:migrations:migrate --no-debug 
In srcLocalProjectContainer.php line 1670:
                                                                               
  Attempted to load class "ContainerAwareEventDispatcher" from namespace "Sym  
  fony\Component\EventDispatcher".                                             
  Did you forget a "use" statement for another namespace?

There were all packages in the composer before this 3.4, then another developer updated to 4.1, now I rebuilt the virtual box, and ran composer install which updated all vendor packages to 4.1, and migrations began to fall.
Why?

Answer 1

This class has been removed in 4.0, as noted in the Changelog . Check that your application does not use (and does not include through use) this class anywhere.