On top of $entity->setRevisionUserId($this->currentUser->id()); it also needs a $entity->setRevisionCreationTime(time()); otherwise the revision is stuck on the previous modification date.
Indeed, could it be that the switch from Swiftmailer to Symfony Mailer has introduced these fields ?
In our case, it seems preferable not to add those fields to the existing forms.
Current workaround : cf. patch attached.
Paulmicha → created an issue.
I got the error too, exactly as described. Drupal core 10.1.2 , ckeditor5_show_block 1.5.
It seems upgrading the NPM dependencies to latest versions and rebuilding the plugin fixes the issue.
This may happen when some code calls something like :
$entity->get($field)
with a field that is not present on given entity.