The support team contacted me and it took them a night to fix it.
The info they gave me, is that they had to install a never version of mariadb from https://autoinstall.plesk.com. After that I could login into the control panel as well as into the panel for the individual domains.
Everything...
Sorry, I obmitted that I'm running Ubuntu. rpm -q obviously doesn't do anything on my system... (I substituted the command with "dpkg -s sw-engine plesk-lmlib", I hope that's ok...)
here is the output:
# ls -lR /var/lock/lmlib/
/var/lock/lmlib/:
insgesamt 0
drwxrwx--- 3 root lock-manager...
I have a V-Server account with Strato and just upgraded to 12.0.18 through the panel updater. The installation completed successfully, at least the installer gave me no error.
After the installation I tried to login and got the following error (I wasn't able to enter my credentials..):
I...