New versions of Portainer generally include a bump to the database schema version - this allows us to make changes to the database structure to accommodate new features, for example. As such, you're unable to use newer databases on older versions.
When updating Portainer we recommend taking a backup first in case you need to roll back. You can then wipe your installation and restore from the backup during reinstallation.
What if I don't have a backup?
If you didn't take a manual backup before updating, you can instead manually restore the database backup taken automatically during the update process. This is a backup of the portainer.db database only and is stored in the portainer_data volume, under the backups directory, named portainer.db.bak. You can use this backup to roll back to the previous version by doing the following:
- Stop and remove your Portainer container (don't delete the
portainer_datavolume!) - Rename the existing
portainer.dbdatabase in the base of theportainer_datadirectory to something likeportainer.db.oldversion(just in case something goes wrong) - Copy the
backups/portainer.db.bakfile toportainer.dbin the base of theportainer_datadirectory - Start Portainer using the image version you were previously on (this must match the version of the backed up database or Portainer will fail to start).