Have you tried to run a rm ~/.cache/desktop-couch ~/.config/desktop-couch and ~/.local/share/desktop-couch and then start gwibber again (running latest version of gwibber 2.29.95)?
Have you tried to run a rm ~/.cache/ desktop- couch ~/.config/ desktop- couch and ~/.local/ share/desktop- couch and then start gwibber again (running latest version of gwibber 2.29.95)?