Which DiskStation model do you have?
DS218+
Ps. The current fix for myself was to revert to PlexMediaServer - 1.16.5.1554 by disabling Plex pass Download option and then downloading. Solved all the issues.
I have my personal copy of some previous X86_64 versions I will make available to you if you wish.
That would be fantastic if you could
Installed PlexMediaServer-1.16.6.1559-a71394a45
Wish I would not have done that…
Getting “Server settings are unavailable”. Can’t get to anything under SETTINGS or MANAGE.
This is awful…
Try this:
So i uninstalled actual version and installed PlexMediaServer-1.16.5.1488-deeb86e7f-x86_64 now everything is working fine for me.
Downgraded, and now everything works fine again.
Worked like a champ… Thanks !
Back on 1.16.5.1544 and can get back to the server settings.
Same problem here. I downgraded back to .1544 and then it works again. (and for anyone reading here, just uninstall Plex and install the old version again, which you hopefully have lying around)
Edit: I am running it on latest DSM on a DS-918+ btw, if that is interesting to know.
I’m having the same problem. I don’t know how to uninstall Plex from Synology so I can install older version of PMS. Please help.
It seems lot of people using synology having the same issue. Won’t it be better to diable that version to avoid more people getting locked out from the server settings?
If you go to https://www.plex.tv/nl/media-server-downloads/ and turn off the option "Plex Pass-download, you get the 1.16.5.1554 version.

Sometimes PlexPass Beta has issues. Unfortunately, this is one of those times.
Same here.
But… what about the 1559 update? Are we going to skip it?
totally understandable… thank you for the feedback
Yeap, The next version will like be a patch of 559
Not a patch. It will be more of the new work coming into the next beta as well as the corrections.
Just had a meeting. We’re on this.
I request everyone revert to Public version of PMS. Please don’t use the beta for now until updated.
Reverted to latest public version and it works again now, thanks for the quick support.