SpoilerCould not save child: "Unknown entity type: Magento\Bundle\Model\Selection\Interceptor requested"
That error message appeared after I saved an example of Bundled Products.
I've done but nothing works:
rm -rf var/cache/* var/view_preprocessed/* generated/* pub/static/*
php bin/magento setup:upgrade
php bin/magento setup:di:compile
php bin/magento setup:static-content:deploy -f
php bin/magento cache:flush
php bin/magento indexer:reindex