Just updated from RC2 > RC3. I thought everything went fine, I logged back in as admin etc, all was ok.
But I've just gone to log in as a member (Test account) and received a white page with the below, Looks like it's something to do with the Oauth stuff? I do have facebook details entered for Oauth.
Catchable fatal error: Argument 6 passed to phpbb\auth\provider\db::_construct() must implement interface Symfony\Component\DependencyInjection\ContainerInterface, string given, called in /websites/123reg/LinuxPackage23/la/mi/n/eg.co.uk/public_html/domains/prewheeleduk/phpbb/auth/provider/oauth/oauth.php on line 163 and defined in /websites/123reg/LinuxPackage23/la/mi/n_/eg.co.uk/public_html/domains/prewheeleduk/phpbb/auth/provider/db.php on line 48