Plex Just Randomly Deleted My Server

Plex Media Server
6

Tread lightly. You should never let an SSD system drive run that full.
(Particularly if you haven’t applied an “over-provisioning” partitioning. https://www.seagate.com/de/de/tech-insights/ssd-over-provisioning-benefits-master-ti/ )

This appears to be the main issue.
Determine where your old Plex data are residing. (I suppose somewhere on D: )

  1. shut down the server using its tray icon
  2. delete the file Preferences.xml from this location: C:\Users\aaron\AppData\Local\Plex Media Server
  3. edit your registry and put in the LocalAppData key to point to your old plex data. See [HowTo] An extended guide on how to move the Plex data folder on Windows for a reminder how it’s done.
  4. while you are in the registry, edit the key ProcessedMachineIdentifier to the value of your old server. How to determine that value is covered in this post: Notice: Users running the Windows version of Plex Media Server