We are trying to upgrade from OwnCloud 9.1.7 and Ubuntu 14.04 to Owncloud 10.x and Ubuntu 16.04 but having no luck. We have tried different orders (Owncloud Update --> Ubuntu Update --> Apache Update) or (Ubuntu Update --> Apache Update -->Owncloud Update) and we get the same results. Once the Ubuntu and Apache Updates run we can’t access OwnCloud anymore. When we go to the main url cloud.xxxx.org\index.php we get a 404 error with The requested URL /index.php was not found on this server. If I remove the index.php part I can get to a bunch of directories but no pages that will load.
this sounds to me like either the Ubuntu or the Apache update is removing / breaking the Apache configuration used to access ownCloud. Maybe you can review the vhost configuration of Apache to see why ownCloud can’t be accessed anymore?
Have a look in your backup from before the upgrade, there you should be able to see the old (working) Apache configuration. Compare it with the current configuration, I bet the upgrade overwrote yours with the standard configuration.
As far as I can tell Apache 2.4 was already available in Ubuntu 14.04 but I would recommend to ensure you didn’t have version 2.2 installed as some directives have changed between versions and configuration files are not compatible.