If restarting etc has no effect, then I imagine this is not unsimilar to other errors where upgrading didn’t fully complete.
I would…
- Set up SSH
- SSH into the Nextcloud container
sudo podman exec -it nextcloud.embassy bash
3). Run…
sudo -E -u www-data php ./occ upgrade
…
I’d also say Nextcloud is one of those things you really out to take a backup of before you upgrade.