Upgraded via admin, on composer installed Magento 2, upgrade reports success. Even though logo and menu and styles show, my store front page only displays this message, instead of the usual frontpage images. Everything is vanilla with sample products.
Error filtering template: Unable to write file into directory /var/www/html/magento2/pub/media/catalog/product/cache/1/small_image/240x300/beff4985b56e3afdbeabfc89641a4582/m/b. Access forbidden.