Continuing the discussion from Cant update EmonCMS via GUI:
Please do not update to version 11.6.8
11.6.8 has a bug that will prevent you being able to update your system via the UI.
If you have updated, you need to switch to the master branch (rather than stable) via the CLI.
SSH into your system
cd /var/www/emoncms/
git pull
git checkout master
When a new release comes out update first before switching back to stable.