imagealphablending(): Argument #1 ($image) must be of type GdImage, bool given

#0 /www/htdocs/w0195ff6/herbstcamp-gp.de/profil/lib/contentfly/Classes/File/Processing/Image.php(100): imagealphablending(false, false)
#1 /www/htdocs/w0195ff6/herbstcamp-gp.de/profil/lib/contentfly/Controller/FileController.php(321): Areanet\PIM\Classes\File\Processing\Image->execute(Object(Areanet\PIM\Classes\File\Backend\FileSystem), Object(Areanet\PIM\Entity\File), NULL, NULL)
#2 /www/htdocs/w0195ff6/herbstcamp-gp.de/profil/vendor/symfony/http-kernel/HttpKernel.php(151): Areanet\PIM\Controller\FileController->getAction('102', 'wannenwetsch-lo...', NULL, NULL)
#3 /www/htdocs/w0195ff6/herbstcamp-gp.de/profil/vendor/symfony/http-kernel/HttpKernel.php(68): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#4 /www/htdocs/w0195ff6/herbstcamp-gp.de/profil/vendor/silex/silex/src/Silex/Application.php(496): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#5 /www/htdocs/w0195ff6/herbstcamp-gp.de/profil/vendor/silex/silex/src/Silex/Application.php(477): Silex\Application->handle(Object(Symfony\Component\HttpFoundation\Request))
#6 /www/htdocs/w0195ff6/herbstcamp-gp.de/profil/lib/contentfly/bootstrap-web.php(146): Silex\Application->run()
#7 /www/htdocs/w0195ff6/herbstcamp-gp.de/profil/index.php(2): require_once('/www/htdocs/w01...')
#8 {main}