After a restore Yunohost is working, but apps (NC, ttrss) show just a blank page

Hardware/OS:
running on an odroid xu4, Debian 9.11 - Armbian 5.41 - 4.14.141 kernel version

YunoHost version:
3.6.4

Description of my issue

Because of an unfortunate hdd failure, I had to restore my backup via rsync (hadn’t a dd of the harddrive) and everything is working normally, but the yunohost apps. It seems, that something is missing, and I can’t find the culprit.

In my nginx-error log I can find this line
PHP message: PHP Fatal error: Uncaught Error: Class 'OC' not found in /var/www/nextcloud/status.php:38

Nextcloud throws the usual internal server error message, which isn’t really helpful, the other apps (ttrss, wallabag) show just a blank page.
-> Reinstalling the apps is not an option
-> Installing new apps (tried bitwarden) just doesn’t work, but I don’t get a usefull error message, it just fails…
here’s the log for it:
pastelog

Thank you for your help!

The issue with Bitwarden is unrelated to the nextcloud issue :


2019-10-06 10:24:18,136: DEBUG - + sudo yunohost app register-url bitwarden teamsan.dedyn.io /
2019-10-06 10:24:19,038: WARNING - Diese URL ist nicht verfügbar oder wird von einer installierten Anwendung genutzt:
2019-10-06 10:24:19,042: WARNING -  * teamsan.dedyn.io/ttrss/ → Tiny Tiny RSS (ttrss)
2019-10-06 10:24:19,043: WARNING -  * teamsan.dedyn.io/nextcloud/ → Nextcloud (nextcloud)
2019-10-06 10:24:19,044: WARNING -  * teamsan.dedyn.io/wallabag/ → Wallabag (wallabag2)

Bitwarden requires a “full domain” so no other apps can be installed on this domain prior to the install of bitwarden

I’m doing yunohost backup restore now and reinstalled the whole OS beforehand.
So this can be closed again.