I do have the exact same problem: audio devices enabled but none can be selected.
I have updated a DS918+ to DSM 7. Uninstalled old Roon package and installed beta version 20210727.
Any idea what I can try?
I have a lot of such lines in the log file at RoonServer/RoonOnNas/RoonServer/Logs
08/02 18:18:19 Debug: NotifyCorruptZoneDatabases Exception LevelDb.Exception: IO error: /volume1/RoonServer/RoonOnNAS/RoonServer/Database/Core/34d652113a194d399c00aa17041d43e6/transport/zone_16010737d24f656a0ba48ee7021d4a11dc00.db/LOCK: Permission denied
I have, with Syno interface, removed the permissions for RoonServer account on RoonServer directory, applied it and set it again and re-applied. Roon was stopped during this, after launching I can now select 1 device, all others I still can’t.