For retro compatibility sake

lib/AppInfo/Application.php

@@ -28,6 +28,7 @@ use OCP\AppFramework\Bootstrap\IBootstrap;
 use OCP\AppFramework\Bootstrap\IBootContext;
 use OCP\AppFramework\Bootstrap\IRegistrationContext;
 use OCP\EventDispatcher\IEventDispatcher;
+use Symfony\Component\EventDispatcher\GenericEvent as OldGenericEvent;
 use OCP\EventDispatcher\GenericEvent;
 use OCP\IUser;
 use Psr\Log\LoggerInterface;
@@ -57,7 +58,7 @@ class Application extends App implements IBootstrap {
 
 		// first time login event setup
 		$dispatcher->addListener(IUser::class . '::firstLogin', function ($event) use ($jobList, $logger) {
-			if ($event instanceof GenericEvent) {
+			if ($event instanceof GenericEvent || $event instanceof OldGenericEvent) {
 				$logger->debug("Trigger of::firstLogin");
 
 				/**