Blank Screen after hostname fiasco

while creating a hostname for another site on my VPS, my host deleted my mysql hostname as well as my domain. This was causing 500 Internal Server Errors. It took me some time to figure that part out, but once I realized that I had a connection issue, I found it and recreated the hostnames as they were, so no configuration script editing was needed.

However, now, when I go to my owncloud installation, it doesn't give an error, but just a blank screen. I tried truncating the oc_filecache table but that didn't help. Any other ideas?

Steps to reproduce
1. Go to

Expected behaviour
Should load the login screen

Actual behaviour
blank screen

Server configuration
Operating system: Linux - Debian
Web server: Apache
Database: mysql
PHP version: 5.6
ownCloud version (see ownCloud admin page): I think 9. I can't get to it right now
Updated from an older ownCloud or fresh install:
Special configuration (external storage, external authentication, reverse proxy, server-side-encryption): lots of external storages defined.

owncloud.log error:
{"reqId":"WJu8Hs3E00MAAEr3AhIAAAAA","remoteAddr":"","app":"PHP","message":"Class 'OC\Files\Cache\Updater' not found at \/home\/[USERNAME]\/[HOSTNAME]\/cloud\/lib\/private\/files\/view.php#99","level":3,"time":"2017-02-09T00:47:26+00:00"}

php.log error:

[09-Feb-2017 00:30:22 UTC] PHP Fatal error:  Class 'OC\Files\Cache\Updater' not found in /home/[USERNAME]/[HOSTNAME]/cloud/lib/private/files/view.php on line 99

Integrity status for oC9+

Looks like you're missing some files or similar. Maybe try to start again with a fresh installation or similar.

I'm having the exact same problem after an automated upgrade.
If I do a fresh install, what about my data???

Strange: I did a delete and restore of the complete owncloud directory on the server, but still get the same error.

Any hint?