I tried again, it ran fine on 25.1 overnight and this attempt it crashed immediately during the update process to 25.1.12 whilst it was updating openssl. I submitted crash reports but the logs are so verbose I am just not able to identify a cause.
I decided to take different approach and downloaded the 25.7 img and installed that this morning, installed fine but did then 2 crash and reboots in the first hour.
The system was however stable enough for me to find 3 plugins in error, I was able to resolve these by using 'Reset All Conflicts' in the Audit tools and followed by a reboot things seems to have improved i.e. no crashes for the last 2 hours
I did look at firmware updates for my board, but the CWWK website put me off, best description of their support website is by another user I came across who called it "a dumpster fire", I got a BIOS image but I think its very much a last resort as I have read a few bad reports about BIOS updates going wrong.
So far so good
C