Hi Trumpy81
Same problem again just happened after installing latest update on Synology.
So thought I would try it myself but didn’t go well. I downloaded the latest version of Plex which was the same as the one I already had. Deleted the Plex app from Synology. Then manual install the downloaded file asks me for token so got that copied in and everything seemed ok and I can log into Plex again. Only I have no library do you have any idea where I went wrong.