We too are migrating away from owncloud by following the migration guide. However, our installation is owncloud 10.12.1.3. We can’t seem to migrate it. We have tried nextCloud version 25.0.2 and 25.0.5 and both return
Exception: Updates between multiple major versions and downgrades are unsupported. Update failed
Does anyone have a suggestion? Or do we need to use nextCloud version 26?
You will perhaps go around the warning with the version downgrade. Not sure if the versions make a lot of sense since the development of NC and OC have diverged since the fork.
I’d certainly keep a backup of the old version, not sure how well the migration scripts are tested. Since OC is moving away from php, it probably would make sense to check with the latest version and provide a good migration tools for users who want to move.