Hi,
I’m sorry for my probably very simple to solve upgrade problem here, but I’m stuck and I don’t know what to do anymore 
It’s not my first owncloud or nextcloud upgrade, so I did what I always do:
mv nextcloud nextcloud.old
tar xf nextcloud10…
cp -r nextcloud.old/data nextcloud/
cp nextcloud.old/config/config.php nextcloud/config/
chown -R www-data:www-data nextcloud
cd nextcloud
sudo -u www-data php occ upgrade
Here I’m getting an error, that Nextcloud can’t connect to the database: http://pastebin.com/udPfSKpQ - but the database is in data/owncloud.db, it has sufficient rights and I can even open it manually by issuing: sudo -u www-data sqlite3 owncloud.db and I can do an .open on it and see all the oc_* tables when running the .tables command.
The most problematic thing is that even a rollback to the old nextcloud by exchanging the directories again does not work anymore. Then I get the same error (even though it’s completely the old state). What did I do wrong to screw things up so badly that I can’t even use the old nextcloud folder anymore? Please help me!
Thanks in advance,
Marius