Could you please elaborate? You just chose Plex in the Package Center, Uninstall, then Manual Install to install the latest package? All your Plex data was left intact?
I never uninstalled Plex before, but looks like this FAQ recommends uninstalling before every update: Synology FAQ (DSM 5 & 6) - Questions, Answers, and a few How-To's - #14 by ChuckPa
