Just to confirm. I have Rock installed on two NUCS and transfer the license regularly. I switched successfully last week from the last version of Rock to the previous version. Today I tried to switch the license back and I did ran into the above issue. After renaming the RoonServer folder and restoring the backup I was able to transfer the license back and everything seems to be working again. In four weeks I will have to transfer the license again and it would be nice if this bug would be fixed before then.