Yes I understand that the migration script was designed for an older version of UNA. As Dolphin has been legacy software for many year now, most sites migrated to UNA some years ago, you will find many of them in the community who followed the migration pathway. There may be various issues with your Dolphin site that are preventing a clean migration, I am not a developer, but I am sure that if you were keen to forge ahead, one of our devs could successfully support you to fulfill this mission. Certainly you could migrate to Drupal or another CMS, but assuming that your site is a social community, UNA is the best platform for building social communities on the planet, with a vast web of integrated (and stable!) features, so I'm not sure why you would choose to go in another direction?

As Cem points out above, UNA 12 was stable, UNA 13 was stable and UNA 14 is stable, most errors reported seem to be settings rather than software, I have been made aware of no roadblocking issues with UNA 14 updates.