i would make a backup of the datadir, delete the database and use "mysql_upgrade --force" after that because this database don't contain any persistent data and should be automatically created
I cannot delete it, Access denied! I did on the commandline as root: MariaDB [(none)]> DROP DATABASE information_schema; ERROR 1044 (42000): Access denied for user 'root'@'localhost' to database 'information_schema' But a look into my permissions, I get all 'Y' for: SELECT * FROM mysql.`user` u where User = 'root' So I think I have a big problem now, havent I? All databases of my applications on this server might work at the moment, but I think it is a question of time, till I run into a severe problem, with this issue. I want to fix this.
before using that big hammer try "mysql_upgrade -u root -p --force" and restart the service after that, maybe that's enough
This was the first thing I had done, after mariadb told me, that I have to use --force, but without any change.