I have a problem with Premium Pass or Server library database or Disc

Sometimes I will find that the music library is empty after 2 or 3 days

The library is listed
All the media is gone
All the playlists show the length of the library
When I click them they are empty

How do I track down to see if its a problem with the Premium pass?
How do I track down to see if its a problem with the music library database(log)

When I select update library for my music
It will take 3 or 4 scans of the library to read the full set of songs
It will scan and find some of the music over again
It will skip some music

It will work for a few days

Library remains
Music gone
Have to rebuild the library

Library has about 8000 songs when its “normal”
About 65 GBs of music
music is just set up as
Artist->Album-Tracks

OS 10.11.5
Mac Mini 2.6 Ghz
8GB Ram
WD 2 TB MYCloud Personal NAS
Plex Version 1.0.3.2461
I have a Music library, a Movie Library and a TV Library
Moviecloud MusicCloud TVcloud

I would have thought that the server would keep the entire list of songs, and if a disk error, show the song in the Music library as “Unavailable”

My Video and TV library don’t show any of these symptoms, so I don’t think its a disc issue but the libraries are not as big
The TV Library is about 1000 Episodes
The Movie Library is about 130 items

Does a library have a recommended size (?)

Another issue that might be related and makes me think its a Plex Premium issue
Each time the music disappears on my media server, the synced media from the library disappears from my iPhone

The music folder on the iPhone is gone

The playlist says I have 1Hr 36 minutes of music in a playlist that I synced
Sync screen says
Waiting for server
Some media appears in the sync screen and says
The path is invalid

I have been running plex for a while and have log files if it helps
(I must have log files in 4 or five locations on my server…)

Sorry this is so long…

I’d start with disabling; auto refresh, butler update of music, empty trash etc. Basically remove any feature in Plex that could potentially remove or update anything automatically, especially re music settings https://support.plex.tv/hc/en-us/articles/200392106-Library-Actions
Optimize the database followed possibly by a manual scan of your database to check for potential errors might also be useful https://support.plex.tv/hc/en-us/articles/201100678-Repair-a-Corrupt-Database

Thanks
I do wonder how this would impact the sync that i performed onto my iPhone

A follow up question
Is it normal for the Plex Music library to just drop all of the files?

I hope this helps my library lasts for more than 3 days without the error!