Hi Adam, sorry for the very late reply. I also found out that the "mgr/cephadm/upgrade_state" config key was the issue. I actually just modified the config key and removed the unknown fields. This made "ceph orch" commands work again. Great. However, the downgrade process was quickly stuck on another step, with a similar message: ``` 2023-03-28T16:05:40.820967+0200 mgr.naret-monitor02.ciqvgv [WRN] unable to load cached state for naret-monitor01: DaemonDescription: __init__() got an unexpected keyword argument 'cpu_percentage' 2023-03-28T16:05:40.821262+0200 mgr.naret-monitor02.ciqvgv [WRN] unable to load cached state for naret-monitor02: DaemonDescription: __init__() got an unexpected keyword argument 'cpu_percentage' 2023-03-28T16:05:40.821499+0200 mgr.naret-monitor02.ciqvgv [WRN] unable to load cached state for naret-monitor03: DaemonDescription: __init__() got an unexpected keyword argument 'cpu_percentage' 2023-03-28T16:05:40.822704+0200 mgr.naret-monitor02.ciqvgv [WRN] unable to load cached state for naret-osd01: DaemonDescription: __init__() got an unexpected keyword argument 'cpu_percentage' 2023-03-28T16:05:40.823935+0200 mgr.naret-monitor02.ciqvgv [WRN] unable to load cached state for naret-osd02: DaemonDescription: __init__() got an unexpected keyword argument 'cpu_percentage' 2023-03-28T16:05:40.825008+0200 mgr.naret-monitor02.ciqvgv [WRN] unable to load cached state for naret-osd03: DaemonDescription: __init__() got an unexpected keyword argument 'cpu_percentage' ``` I did not find a solution to this, and as the downgrade process was again stuck, we finally decided to move forward and try a major upgrade to Quincy, version 17.2.5. The upgrade succeeded and everything is working fine now. It seems that the downgrade is not supported and, unfortunately, testing the upgrades in a test environment is not sufficient. We tested the upgrade on a small test cluster, and everything went fine, but when we did the upgrade on a much bigger production cluster this issue showed up: https://lists.ceph.io/hyperkitty/list/ceph-users@ceph.io/thread/53NNVLLKLMYV... and we were therefore blocked. Luckily we found a solution in the end :) Thanks anyway for your help! Best Regards, Elia Oggian