Hi all,
I have a RPi 3b+ with a WD PiDrive 250Gb attached, I just updated to 2.673 (released today 1/12/19) and really wish I hadn’t. The system no longer had any local files listed after a restart. Worse still, if I try to rescan or update it just restarts the Pi, so I can’t get the system back to where it was before I updated.
The irony is, I was about to carry out an SD card back up but for no discernible reason I saw an update was available and did that first - DOH! So it looks like I will have to re-burn the sd card with the Volumio image I have stored on my pc, rebuild the local files and reinstall the plugins I have. This is doubly annoying as I have pydPiper running a 16x2 LCD and that took me AGES to get working. I’ll also have to redo all my playlists 
So, if you have a locally stored library - DO NOT UPDATE!!! Not until this bug is fixed anyhow. In case anyone asks, I’ve checked the hard drive on two separate machines - one Windows and one mac OS and it’s totally fine. I’ll hang on with things as they are for a while before I reinstall, in case anyone needs me to check something or whatever to help diagnose what’s gone wrong, but bear in mind you may need to explain how to extract relevant information as I’m not a Linux expert.
I believe that your manual modification somehow messed up the system, and mpd cannot start after the update.
Just check mpd log in /var/log/mpd and see if you can understand why it does not start.
What do you mean by "manual modification? If you mean the lcd screen, it’s been running fine for weeks with it, everything went wrong only when I did the update just now. Unless you’re suggesting a plugin has somehow interfered with the update somehow? I don’t know, could it? The plugin is just the basic configuration I am sure lots and lots of Volumio users have on their systems so if the update is incompatible with the plugin then they all need warning yes?
Also, I’m looking in /var/log now via ssh and I do not have an mpd log, I have:
boot.log
btmp
pydPiper.log
volumio.log
wtmp
Reading both the boot.log and volumio.log files there are no errors being reported that I can see - I’m no expert mind but all the entries are just ‘starting <whatever service/process etc>’ followed by a <[OK] started <whatever service/processes> > message. I can’t see a specific entry for MPD but there are some entries relating to MPD such as ‘Starting UPnP Renderer front end to MPD’ for instance. I certainly do not see anything that would suggest what has gone wrong in any of these logs.
UPDATE
Alright, I’ve done quite a bit of testing. I wrote a fresh image to the sd card, and then reinstalled the pydPiper plugin. Everything was fine.
Next I started again with a fresh install again, but this time I carried out the update. I have noticed a different issue at this point - browsing the locally stored files is significantly slower than before the update. The green progress bar at the top seems to hang just before it reaches the end, for a few seconds, sometimes slightly longer than that. Anyway, I reinstalled the pydPiper plugin and again everything ‘broke’. So something dies either if you install the update first, or after the pidPyper plugin, and it is definitely the plugin that is the issue.
Finally I started again by writing a backup of the previously configured image - that is an image with some of my settings, and standard ui installed plugins, but not the new update. I am currently reinstalling the plugin but I am not updating when its done!
So I reiterate - if you have the pydPiper plugin installed don’t update for now, at least until someone who knows what they’re doing can figure out what is happening.