To confirm:
-
You can still see all your metadata in the old “Plex” shared folder under “Library/Application Support/Plex Media Server” ?
-
Presuming you can - Uninstall the existing package + ERASE option to remove the errant DSM 7 installation.
-
Now install PMS 1.24.2.4973 (or higher) and follow the instructions for setting all the permissions (these are needed because DSM 7 made us change username from Plex → PlexMediaServer and normal linux rules say we can’t read another user’s data)
-
Depending on size of data, it can take a few hours. Don’t worry. Let it run. It won’t “Hang”.