Thanks. Worked for me.
It needed to do a reboot after the “sudo apt-get upgrade”.
Just FYI for others, the 4 steps listed by borpin worked for me. I’ve been running my Pi with the emonSD-17Oct19 (Stable) image since Nov 2019. In April 2020 it was emoncms low-write version 10.1.13, then when I went to create backups last week, it was version 10.2.6 and the service-runner had stopped working. From the Pi’s system prompt, sudo apt-get upgrade upgraded 152 things. I did the python3-pip and redis installs, but already had the latest versions. After a reboot, the Admin page shows I’m still running 10.2.6 and for OS, Linux 5.4.51-v7+. Service-runner is now running and I just finished creating a backup. If I can find a way to install the emonSD-24Jul20 release and keep my existing Dataplicity wormhole URL, I’ll do it (seems that’s not possible, but if you know a way, let me know!).Thank you borpin and other contributors to this thread.
If you are using the free version, can you not just deauthorise the current install, and reinstall?
@TrystanLea, just tripped over this. PR to fix.
Will not fix it for anyone upgrading before this is merged.
Lets hope it fixes it 
I have just installed using EmonScripts onto the Raspberry Pi3 (Buster Lite dated 20-August) and found service-runner not working;
sudo pip3 install redis
Seems to have fixed it.