Recoverable error: Argument 1 passed to Contao\Image::__construct() must be an instance of Contao\File, null given, called in /var/www/vhosts/h258260.web132.alfahosting-server.de/html/contao2017/system/modules/core/library/Contao/Image.php on line 898 and defined in system/modules/core/library/Contao/Image.php on line 107
#0 system/modules/core/library/Contao/Image.php(107): __error(4096, 'Argument 1 pass...', '/var/www/vhosts...', 107, Array)
#1 system/modules/core/library/Contao/Image.php(898): Contao\Image->__construct(NULL)
#2 system/modules/core/library/Contao/Controller.php(1534): Contao\Image::create(NULL, Array)
#3 system/modules/pageimages/modules/ModulePageImages.php(54): Contao\Controller::addImageToTemplate(Object(Contao\FrontendTemplate), Array)
#4 system/modules/core/modules/Module.php(287): PageImages\ModulePageImages->compile()
#5 system/modules/pageimages/classes/PageImages.php(27): Contao\Module->generate()
#6 system/modules/core/library/Contao/Controller.php(321): PageImages\PageImages->generate()
#7 system/modules/core/pages/PageRegular.php(137): Contao\Controller::getFrontendModule(Object(Contao\ModuleModel), 'slider')
#8 system/modules/core/controllers/FrontendIndex.php(285): Contao\PageRegular->generate(Object(Contao\PageModel), true)
#9 index.php(20): Contao\FrontendIndex->run()
#10 {main}

Fatal error: Call to a member function exists() on null in /var/www/vhosts/h258260.web132.alfahosting-server.de/html/contao2017/system/modules/core/library/Contao/Image.php on line 110