mattjm

That sounds like a Klipper message, not from the armbian OS. If there is new functionality in Klipper it will show this error, but you don't always need to reflash the MCU depending on if you use those functions. You can post in a more detailed error and versions in a Klipper forum for advice.

I ran into this as well. Downgrade to kernel 6.12.58 fixed the physical interface. My board that initially had Trixie required the NetworkManager fix to get wifi working even after reverting. Something about the upgrade and/or downgrade broke netplan.

As a data point, I had a CB1 with Trixie that was working fine with netplan until I did an apt upgrade to 26.2.1 and kernel 6.18.xx. The upgrade made my physical interface disappear, which required a kernel downgrade (to 6.12.58) to get back. But even after the downgrade my wireless interfaces still wouldn't connect. The ultimate fix was to switch this board to NetworkManager like I did with my other CB1 that was running bookworm and required the NetworkManager fix from day one.