I recently set up a new iMac (running Catalina) and installed the latest Plex Media Server. When I tried to add my media from the external hard drive I had used with my previous iMac and Plex Media Server without issue, it has accepted the pathway however no media items are showing in any of my libraries.
It was so easy to setup last time, I don’t even know where to start now that there is a problem…
Ok, this is a security setting in Catalina MacOS 10.15.
System Preferences / Security & Privacy/ Privacy
In the left panel scroll down to Files and Folders, in right panel go down to Plex media server and enable access to Removable Volumes. Restart Plex Media Server.
Re. folder content not available when accessing USB-connected APFS drive/folder on Mac Catalina, having tried all solutions proposed, (e.g. changes in privacy settings, shared settings, share-only user names, SMB enabled, you name it) – all to no avail…, only thing that worked was selecting library type 'Other Videos" and not ‘TV Shows’ or ‘Movies’, (despite what may be TV or Movie ‘content’) and only then did all .avi and .mp4 files, etc. scan correctly and show up as thumbnails, and visible/playable via Plex or Infuse client. What a pain – wish this workaround were better documented and more widely known…