I upgraded z2m but it fails due the old hardware (old CC2531).
I tried to downgrade but it fails.
So I simply removed the dir /opt/zigbee and I copied an old one from my backup (with all files).
It starts but the log of z2m says that 0 devices are paired.
I can restart all the system from an old backup, but I am going to lose a month work!
I was thinking that I could restart everything with the /data dir.
Thanks