WCF::handleException() Unhandled exception: Call to a member function getProcessor() on null

#0 /var/www/clients/client6/web15/web/wcf/lib/data/attachment/Attachment.class.php(58): wcf\data\attachment\Attachment->getPermission('canViewPreview')
#1 /var/www/clients/client6/web15/web/wcf/lib/system/event/listener/StatisticsListener.class.php(39): wcf\data\attachment\Attachment->canViewPreview()
#2 /var/www/clients/client6/web15/web/wcf/lib/system/event/EventHandler.class.php(189): wcf\system\event\listener\StatisticsListener->execute(Object(wcf\page\StatisticsPage), 'wcf\\page\\Statis...', 'assignVariables')
#3 /var/www/clients/client6/web15/web/wcf/lib/page/AbstractPage.class.php(113): wcf\system\event\EventHandler->fireAction(Object(wcf\page\StatisticsPage), 'assignVariables')
#4 /var/www/clients/client6/web15/web/wcf/lib/page/StatisticsPage.class.php(26): wcf\page\AbstractPage->assignVariables()
#5 /var/www/clients/client6/web15/web/wcf/lib/page/AbstractPage.class.php(182): wcf\page\StatisticsPage->assignVariables()
#6 /var/www/clients/client6/web15/web/wcf/lib/page/StatisticsPage.class.php(37): wcf\page\AbstractPage->show()
#7 /var/www/clients/client6/web15/web/wcf/lib/page/AbstractPage.class.php(86): wcf\page\StatisticsPage->show()
#8 /var/www/clients/client6/web15/web/wcf/lib/system/request/Request.class.php(58): wcf\page\AbstractPage->__run()
#9 /var/www/clients/client6/web15/web/wcf/lib/system/request/RequestHandler.class.php(108): wcf\system\request\Request->execute()
#10 /var/www/clients/client6/web15/web/index.php(9): wcf\system\request\RequestHandler->handle('news')
#11 {main}