xDM

Is it possible to downgrade between versions of xDM?

Patches: you can rollback (or forward) between patches. For example, between version 5.2.1 and 5.2.7

Minor Upgrades (changes between .X)

While upgrades between .X versions are supported, downgrades are not. Minor upgrades require updates to the repository. Once completed, this operation cannot be reversed. For example, attempting to rollback from version 5.2.0 -> 5.1.6 will result in an error similar to the one below. More details can be found in the Upgrade Guide.