Thank you for posting this image
I found out that I was a little lazy when reading Apple's example: I didn't open the bundled DB but the one in the application folder. Because I haven't copied it in there first it gave me an error when trying to open it. I didn't realize my fault because it created the file in the Documents directory because it was not there. And I thought that creating a temporary copy is standard behaviour.
So this
solves my first problem.
But the
second one is still occuring. Any thoughts?