Cannot use object of type news\system\attachment\NewsAttachmentHandler as array

Stacktrace:
#0 [internal function]: news\data\news\NewsAction->update()
#1 /srv/www/htdocs/www.skorpionforum.com/lib/data/AbstractDatabaseObjectAction.class.php(204): call_user_func(Array)
#2 /srv/www/htdocs/www.skorpionforum.com/news/lib/system/worker/NewsRebuildDataWorker.class.php(156): wcf\data\AbstractDatabaseObjectAction->executeAction()
#3 /srv/www/htdocs/www.skorpionforum.com/lib/acp/action/WorkerProxyAction.class.php(92): news\system\worker\NewsRebuildDataWorker->execute()
#4 /srv/www/htdocs/www.skorpionforum.com/lib/action/AbstractAction.class.php(47): wcf\acp\action\WorkerProxyAction->execute()
#5 /srv/www/htdocs/www.skorpionforum.com/lib/action/AJAXInvokeAction.class.php(63): wcf\action\AbstractAction->__run()
#6 /srv/www/htdocs/www.skorpionforum.com/lib/system/request/Request.class.php(83): wcf\action\AJAXInvokeAction->__run()
#7 /srv/www/htdocs/www.skorpionforum.com/lib/system/request/RequestHandler.class.php(96): wcf\system\request\Request->execute()
#8 /srv/www/htdocs/www.skorpionforum.com/acp/index.php(9): wcf\system\request\RequestHandler->handle('wcf', true)
#9 {main}