Thank you. That tells me everything I need to know.
It confirms you made a mistake when you attempted to upgrade from DSM 6 → DSM 7.
The most common error is forgetting the check the “Apply to this folder, sub-folders and files” box when you give “PlexMediaServer” Full Control of the shared folder.
We can easily recover from this.
- You still have all your Plex server in the “Plex” shared folder.

- We will now erase the broken DSM 7 installation which was created.
- Package Center
- Uninstall the Plex app
- ERASE option (the red one) to remove the empty DSM 7 data.
- Now we give “PlexMediaServer” Full Control of the Plex shared folder
- this can take a long time. It depends entirely on how much media you have indexed. Time is usually 2-3 minutes per 1000 items (videos, music, or photos) Plex has in your libraries
- When this is complete, install any version higher than 1.24.2.4973 . Do not install from the Synology Package Center (1.21.0.3744) as it is incompatible.