You did something wrong.
The DSM installer will take ALL your contents from Plex → PlexMediaServer
so you don’t have to reinstall.
The installer WILL NOT migrate the contents of the Plex shared folder if it sees an existing server in PlexMediaServer. ( I prohibit overwriting an active server ). If you tried to do anything manually, the installer will stay ‘hands off’.
The installer / migration process starts automatically if a valid server is found in the Plex
shared folder.
Have you reviewed?
It details the changes
- DSM 6 → DSM 7 beta
- DSM 7 beta → DSM 7 final
Can you show me what you have in Plex/Library/Application Support/Plex Media Server
?