Fehler bei Upgrade auf PHP 7.2

Hallo zusammen,

bei mir läuft derzeit Shopware 5.3.4 mit PHP 5.5.6. Ich muss zwingend auf >= PHP 7.2 upgraden.

Sobald ich bei meinem Hoster auf >= PHP 7.2 umstelle, erhalte ich im Shopware Front- und Backend folgenden Fehler angezeigt:
 

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Warning: count(): Parameter must be an array or an object that implements Countable in /.../htdocs/engine/Library/Enlight/Event/EventManager.php on line 107

Fatal error: Uncaught Zend_Session_Exception: You must call Zend_Session::setId() before any output has been sent to the browser; output started in /.../htdocs/engine/Library/Enlight/Event/EventManager.php/107 in /.../htdocs/engine/Library/Zend/Session.php:701 Stack trace: #0 /.../htdocs/engine/Library/Zend/Session.php(445): Zend_Session::setId('da374ddbbd813a1...') #1 /.../htdocs/engine/Shopware/Components/DependencyInjection/Bridge/Session.php(105): Zend_Session::start(Array) #2 /.../htdocs/var/cache/production_201710241020/proxies/ShopwareProduction183cd2c84ccbee085532a66c3edcafd5dfec425aProjectContainer.php(1158): Shopware\Components\DependencyInjection\Bridge\Session->createSession(Object(ShopwareProduction183cd2c84ccbee085532a66c3edcafd5dfec425aProjectContainer), Object(Shopware\Components\Session\PdoSessionHandler)) #3 /.../htdocs/vendor/symfony/dependency-injec in /.../htdocs/engine/Library/Zend/Session.php on line 701

Kennt jemand den Fehler oder kann mir jemand dabei helfen?

Vielen lieben Dank!

Also Shopware 5.3 ist nicht kompatibel mit PHP 7.2.

Du musst mindestens Shopware 5.5 dazu einsetzen.