I was experiencing problems with my Synology NAS apps due to the Plex installation not cleaning up after itself. This caused problems using Synology apps.
After contacting Synology support, this is what they came back to me with:
"Dear Customer,
Thank you for contacting Synology support.
We've found the root cause of this issue.
The system partition(/dev/root) was full in your system:
______0.jpg
Which were filled with files should have been deleted by system but stopped by Plex
Plex\x20M 7568 plex 1w REG 9,0 1370160873 22930 /var/log/synopkg.log.1 (deleted)
Plex\x20M 7568 plex 2w REG 9,0 1370160873 22930 /var/log/synopkg.log.1 (deleted)
Plex\x20S 8051 plex 2w REG 9,0 1370161014 22930 /var/log/synopkg.log.1 (deleted)
Plex\x20D 10251 plex 1w REG 9,0 1370163693 22930 /var/log/synopkg.log.1 (deleted)
Plex\x20D 10251 plex 2w REG 9,0 1370163693 22930 /var/log/synopkg.log.1 (deleted)
Plex\x20T 10257 plex 1w REG 9,0 1370163693 22930 /var/log/synopkg.log.1 (deleted)
Plex\x20T 10257 plex 2w REG 9,0 1370163693 22930 /var/log/synopkg.log.1 (deleted)
Hence, a process in PhotoStation failed to write log in system partition that leads to DSPhoto failed to login.
After stopping Plex, the system has successfully deleted these files:
In this case, though we've applied a fixed in your system, it would be great if you can contact Plex for this issue as Plex is not designed by us."****
Funny in that you have to post this issue in a forum and not being able to contact Plex support (non-existent).