There is no playable file (mini-solution)
1. Turn off server in the Serviio console.
2. Erase server in the BDP-S570 menu.
3. Turn off all metadata functions in the Serviio console.
4. Clear all library listings and re-enter, making sure that thumbnail function is de-selected.
5. Force refresh
6. Turn server back on in console.
7. Renew server on the BDP-S570.
After that all files were found and were playable (as long as they were supportable by the transcoding function). I would guess that most of this would not be necessary, perhaps just making sure all metadata functions, including the checkbox in the library section are turned off. I am now immensely happy with a fully functioning Serviio. If Sony ever sends out an update that will allow metadata, I will try turning it back on then.