Thank you so much!! This worked for me. These are the steps I used (although my chmod 666 is overkill. I need to experiment with that one)

sudo chown root: root /opt/local/Online Backup/00000000-0000-0000-0000-000000000000/plans/{a2483730-77c8-451b-aff6-a87bcfb95b0f}.cbb

sudo chmod 666 /opt/local/Online Backup/{a2483730-77c8-451b-aff6-a87bcfb95b0f\}.cbb

sudo systemctl status cloudberry-backup