I can't register an admin

Hello there,
I’ve installed OwnCloud on my Raspberry Pi which is running the latest version of Raspberry Pi OS. I just wanted to build a fileserver and then I had to register the admin. So I got the following error:

Error while trying to create admin user: Failed to connect to the database: An exception occured in driver: SQLSTATE [HY000] [2002] File or directory not found.

Does sombody know, what is meant by that? I searched the internet and no thread could help me!

Thanks in advance for your help!

Using the search function of this forum with “SQLSTATE [HY000] [2002]” delivers 38 hits. And your owncloud.log will deliver more details what went wrong. Good luck!