Exactement la même erreur depuis la mise à jour des modules et le vidage de cache.
Je n'ai plus du tout accès au backoffice:
Whoops, looks like something went wrong.
1/1 RuntimeException in PhpDumper.php line 1403: Cannot dump definition because of invalid class name (NULL)
in PhpDumper.php line 1403
at PhpDumper->dumpLiteralClass('NULL') in PhpDumper.php line 790
at PhpDumper->addNewInstance('_defaults', object(Definition), 'return ', '$this->services['_defaults'] = ') in PhpDumper.php line 394
at PhpDumper->addServiceInstance('_defaults', object(Definition)) in PhpDumper.php line 639
at PhpDumper->addService('_defaults', object(Definition)) in PhpDumper.php line 666
at PhpDumper->addServices() in PhpDumper.php line 145
at PhpDumper->dump(array('class' => 'appDevDebugProjectContainer', 'base_class' => 'Container', 'namespace' => '', 'debug' => true, 'file' => '/homepages/38/d740167929/htdocs/clickandbuilds/PrestaShop/SCRAPNEWAGE/app/cache/dev/appDevDebugProjectContainer.php')) in bootstrap.php.cache line 2846
at Kernel->dumpContainer(object(ConfigCache), object(ContainerBuilder), 'appDevDebugProjectContainer', 'Container') in bootstrap.php.cache line 2759
at Kernel->initializeContainer() in bootstrap.php.cache line 2533
at Kernel->boot() in bootstrap.php.cache line 2564
at Kernel->handle(object(Request), '1', false) in index.php line 86