One or more items failed to play

Hi, I’ve my OSMC devices running with a Synology DS223, nfs and autofs.

Not sure where to start. So, I suggest to check working autofs first:

In this wiki article you find in the initial post a section

For NFS:
Testing the config:

Is this working fine means can you see the files at the location you assume? E.g. In the logs you tried to play file /mnt/Movies/The Lord of the Rings - The Two Towers (2002)/The Lord of the Rings - The Two Towers (2002) Bluray-2160p.mkv.