I’ve not found the root cause, yet. But I’ve managed to get my radicale installation back into working state by doing the following:
- Make a backup copy of all data from
/var/lib/private/radicale - Uninstall
radicalevia plinth web UI - Verify that data folders have been purged, nothing remains
- Reinstall
radicalevia plinth - Check the data folders, they were still missing
- This is not surprising, since
radicaleis activated by socket, so without a connecting client, the service will stay disabled.
- This is not surprising, since
- Connect with a client once, connect & refresh, then verify that the data folders are now existing
- This actually dropped all collections and data from the client since the server-side is blank after reinstallation. But I expected this and I’ve the backup copy made above.
- Copy back my backed up data files into the (now existing) collection folders.
- Make sure permissions are correct by running
chown -R nobody:nogroup /var/lib/private/radicale/collections/collection-root/* - Reload & refresh on the client again. This time, everything is there and synchronization works again

One thing I noticed was that previous to the reinstallation all the data files would belong to the radicale user:group. After reinstallation, all the data belonged to nobody:nogroup, so I adopted this in my last step above. Not sure, but maybe this was somehow contributing to my issues.
Cheers & HTH,
Axel