Still sounds as if there might be something off with the file server or the network if your Pi is having trouble accessing previously accessible files on your file share.
So... you're using the hostname fritz.box in the music source path, try changing this to the server's IP address instead to avoid a possible name resolution issue on your network/router.
But still without knowing more about your system/network there's not a lot to go on. You could give us some info by logging into moode's SSH terminal (Moode menu > Configure > System > Local Services > enable SSH term server > [OPEN] Web SSH Terminal > login as u/n pi & p/w moodeaudio at the prompt) and run;
... and...
Post the output wrapped in code blocks.
So... you're using the hostname fritz.box in the music source path, try changing this to the server's IP address instead to avoid a possible name resolution issue on your network/router.
But still without knowing more about your system/network there's not a lot to go on. You could give us some info by logging into moode's SSH terminal (Moode menu > Configure > System > Local Services > enable SSH term server > [OPEN] Web SSH Terminal > login as u/n pi & p/w moodeaudio at the prompt) and run;
Code:
mount | grep mnt... and...
Code:
moodeutl -sPost the output wrapped in code blocks.
