I didn't change anything here - the installation process used the computername "Wi7LSY5985" to build the pathname. I know this syntax from network mounts; I didn't know that it can be used for local files as well. I tried it - and it works on my desktop computer. But not on my laptop. So there mus be something wrong with my network settings or firewall settings or whatever else.
Maybe someone can tell.
brgds,
Ulrich