After updating Ubuntu server 16.04. No access to OwnCloud is possible with the oc-client and/or oc webinterface

Steps to reproduce
1.Working 9.0.1 OC on Ubuntu Server 16.04
2.Upgrade the latest Ubuntu server patches

Expected behaviour
The OC-client shoud connect as it did before. And it should be possible to login via the web interface, as I could before.

Actual behaviour
The OC-client reports that it can not connect to OwnCloud on my server.
Error downloading https://cloud.yyyy.xx/remote.php/webdav/ - server replied: Not Found
Also if I go to my OwnCloud on: https://cloud.yyyy.xx/index.php then it wants me to login. I fill in my credentials and nothing happens. No error, nothing.

Server configuration
Operating system: ubuntu server 16.04
Web server: Apache/2.4.18 (Ubuntu)
Database: mysql 14.14 Distrib 5.7.13, for Linux 9x86_64)
PHP version: 7.0.8-0ubuntu0.16.04.1
ownCloud version (see ownCloud admin page): sudo -u www-data php occ -V: 9.0.1
Updated from an older ownCloud or fresh install:fresh install
ownCloud log (data/owncloud.log: Log file is empty

Special configuration (external storage, external authentication, reverse proxy, server-side-encryption): No

Integrity status for oC9+

Login as admin user into your ownCloud and access
http://example.com/index.php/settings/integrity/failed
paste the results here.
No results because it's not possible to login.
with occ integrity:check-app
 - EXCEPTION:
  - class: Exception
  - message: App not found
with occ integrity:check-core
 - EXTRA_FILE:
  - owncloud.log:
   - expected:
   - current: cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47415a81a538327af927da3e

make sure that you're running the latest available version for oC 9.0: https://owncloud.org/changelog/#latest9.0

from the issue template shown when creating a new issue in the oC9.0.x category. Your specific issue (compatibility with PHP7.0.6+) is already fixed in the newer releases 9.0.4

Hi RealRancor,

if I use occ upgrade it says: ownCloud is already latest version?
https://doc.owncloud.org/server/9.0/admin_manual/maintenance/package_upgrade.html
didn't solve te problem.

Any suggestions?

Hans

occ upgrade won't download or install any updates nor will it check for new updates. Please read the documentation how to proceed:

https://doc.owncloud.org/server/9.0/admin_manual/maintenance/upgrade.html

Depending on your initial installation way choose the instructions there and proceed with the update to 9.0.4.

I'm closing here for now for the reasons explained in https://central.owncloud.org/t/why-should-i-create-a-new-thread-for-each-question-problem/1123. If you need further help with the update please create a new thread in the help category for oC 9.0.x