I think I have found the problem. The promlem is, that I have set the
right path to the database. I don't know how to set the path to a
database in the source folder, I have tried several ways. What I can
get to work, is to refer to the user home directory, so I will use
that for now. If someone knows how to refer to the source folder,
please show me. I have tried everything, that was in the manual, but
it didn't work.