Ubuntu 14.04 to 16.04 kills owncloud



Please help us by providing the following info. Before posting please also check the pinned "Known issues" threads and make sure that you're running the latest available version for your oC release: https://owncloud.org/changelog/

Steps to reproduce
1. Fully upgraded and patched oc 9.1 server running on fully upgraded and patched Ubuntu 14.04.5 server and already on MariaDB all installed from repos
2. do-release-upgrade to 16.04.1
3. Dead owncloud after restart

Expected behaviour
Normal upgrade

Actual behaviour
Flames, death, screaming

Server configuration
Operating system: Ubuntu 14.04.5
Web server: Apache2 from default repo
Database: MariaDB 5.5 from default repo
PHP version: 5.5.9-1ubuntu4.20
ownCloud version (see ownCloud admin page): 9.1.0
Updated from an older ownCloud or fresh install: updated over time
Special configuration (external storage, external authentication, reverse proxy, server-side-encryption):

ownCloud log (data/owncloud.log)

Please paste possible errors in the following code block, see https://central.owncloud.org/t/how-to-find-webserver-or-oc-logfile-enable-php-logfile/808 for more info

Integrity status for oC9+


Please explain "dead" as you might can guess that this is away to generic that anyone in here can help you with that.