Nextbox image with Nextcloud 24 / upgrade

The Nextbox app does not start any more. I have not used my Nextbox for many months. Trying to connect to the Nextcloud failed. Attempting to get the system running again I did prune unused Docker images (that may have been a mistake).

When I check the logs:

$ sudo docker logs nextbox-compose_app_1 | tail -n 3
Initializing nextcloud 29.0.11.1 ...
Can't start Nextcloud because upgrading from 24.0.6.1 to 29.0.11.1 is not supported.
It is only possible to upgrade one major version at a time. For example, if you want to upgrade from version 14 to 16, you will have to upgrade from version 14 to 15, then from 15 to 16.

How can I use a Nextbox image which uses a compatible Nextcloud version?

Hello,

If you don’t have any important data on your NextBox I would suggest to perform a factory reset by following this guide:

https://docs.nitrokey.com/nextbox/technical/factory-reset

It is good to know that the possibility for factory reset exists - as fallback. But it is quite drastic.

I would prefer backup the current PIM data (calendar, contacts, …) of the Nextcloud users before. I only know how to do this within Nextcloud and that currently does not start…