? in mp3 file name for playlists doesn't work

[simoncn]

I am pleased to hear you have found a way to fix the filenames containing DEL showing as ?.

I don't know what is causing the problem you are having with folder names containing accented characters such as ö so I can't give advice on how to fix this. I have tested this playlists referring to files with Synology folder names containing NFC and also folder names containing NFD. Both of these are working for me. I suspect your folder name Funkstörung might be using some other encoding but I am not sure how to find out what this encoding is.

Are you able to use VFS to successfully fix the problem with the Funkstörung folder?

I have used convmv (the link you posted) and it works well if you know what encoding you have currently and what encoding you want. I suggest you try using convmv on one folder before you run it on your whole library.