I was advised to upgrade to 2.0. After I did, I learned that Mac OSx 10.12 on my Roon endpoint is not supported anymore.
I downgrade the core to 1.8, but the library is inaccessible since. I have no backup, but as /var/roon/roonserver contains 20000 objects (~1GB), I guess the library is still there.
All these 21 albums are stored locally on the same MAC as FLAC-Rips. All the rest (the thousends of albums streamed with TIDAL) is absent.
I don´t find a way to give Roon the information, where my library is.
Could it be that during the update to V. 2.0 my library was transformed in a new format that V 1.8 doesn´t recognize anymore?