Here just a little workaround for Ubuntu 18.04.6 LTS and Gnome 3.28.2. I suppose it could work with other distributions:
1-backup your evolution data 2-install or upgrade evolution from 3.28 to 3.42 via flatpack (https://flathub.org/apps/details/org.gnome.Evolution) 3-import evolution data from the previous backup 4-reboot
and I have all contacts, calendars and tasks working again!
Here just a little workaround for Ubuntu 18.04.6 LTS and Gnome 3.28.2. I suppose it could work with other distributions:
1-backup your evolution data /flathub. org/apps/ details/ org.gnome. Evolution)
2-install or upgrade evolution from 3.28 to 3.42 via flatpack (https:/
3-import evolution data from the previous backup
4-reboot
and I have all contacts, calendars and tasks working again!