To all who are affected by the sporadic "error #67". if you use a self-built battery and have connected it via UART or RS485 adapter, replace the adapter cable with a decent adapter.
in my case, I have replaced my original Daly RS485 -> USB cable with a DSD TECH SH-U11F with matching JST connector and since then not a single error message. The whole thing now runs a good week without any problems.
I have the suspicion that in the original but still cheap adapters the installed chips and / or the thin, unshielded cables can cause problems. the adapter I mentioned works both on the UART and RS485 port!
tested with two Daly BMS on an Easysolar II GX.