Error: InvalidArgumentExpression files_sharing is using the old way to register

Updated to 19.0.0_1 (up to date)
and php73-7.3.19

changes to config.php:

-  'version' => '18.0.4.2',
+  'version' => '19.0.0.12',


-  'app_install_overwrite' =>
+  'app_install_overwrite' => 
   array (
 0 => 'theming_customcss',
 1 => 'metadata',
 2 => 'dashboard',
 3 => 'socialsharing_email',
 4 => 'files_texteditor',
+    5 => 'fulltextsearch_elasticsearch',
+    6 => 'files_fulltextsearch',
+    7 => 'fulltextsearch',
+    8 => 'passman',
   ),

Errors persist:

[no app in context] Error: InvalidArgumentException: Notifier Federated sharing (id: files_sharing) is not considered because it is using the old way to register. at <<closure>>

0. /usr/local/www/nextcloud/apps/federatedfilesharing/appinfo/app.php line 40
   OC\Notification\Manager->registerNotifier(Closure {}, Closure {})
1. /usr/local/www/nextcloud/lib/private/legacy/OC_App.php line 266
   require_once("/usr/local/www/ ... p")
2. /usr/local/www/nextcloud/lib/private/legacy/OC_App.php line 155
   OC_App::requireAppFile(OCA\FederatedFil ... {})
3. /usr/local/www/nextcloud/lib/private/legacy/OC_App.php line 128
   OC_App::loadApp("federatedfilesharing")
4. /usr/local/www/nextcloud/lib/base.php line 992
   OC_App::loadApps()
5. /usr/local/www/nextcloud/index.php line 37
   OC::handleRequest()

GET /index.php/apps/logreader/get?offset=0&count=50&levels=00011
from 185.106.28.207 by gessel at 2020-06-28T09:56:22+00:00

This appears to be a “frequent” error:

# grep "old way to register" nextcloud.log | wc -l
4044

Federated file sharing is disabled in this install.
(all cloud Federated Cloud Sharing options are disabled in “sharing” and the “Federation” app (v 1.9.0) is disabled in “Apps”

(enabling it does not quiet the errors).