Hi the same issue has happened to me, I tried updating my emoncms from version 8.5 and although the updater runs and the emonpi reboots it steadfastly remains at 8.5.
Now I have the same startup error with exactly the same log file as the other user in this thread.
I will try fixing it using the default config as suggested - however I had edited the old one and only got my system (two sensors - a CT1 and an optical) working through a lot of trial and error so I’m worried my nodes won’t be working after updating to the default config file but here goes.
Update: I seem to be back where I started with all my feeds working and accessible from emoncms.org.
This issue started for me when I wanted to upgrade my Emonpi firmware, when I looked here for how to do it the video guide started from the premise that my Emoncms version should be the latest one which is v9.x - mine was running v8.5 and trying to update this was the start of my troubles.
Do you advise going ahead and updating the SD card image anyway without first updating Emoncms to v9.x?
Yes updating from 8 to 9 requires the new SD card image as does adding GSM support it is not possible to update from 8 any further
Glyn I hit this issue tonight with duplicate nodes, can confidently say it was caused by /home/pi/data being out of space and an upgrade attempted FYI
Delete duplicates and rebooted all is well.