For more details on what's new checkout https://www.planarally.io/blog/2020/05/10/release-0-20-0-what-s-new/
This addresses an issue where upgrading older saves had some small mistakes in the past causing a divergence between the schema of new and old saves.
This will rewrite a bunch of your db so the upgrade might take longer than usual.
This will also fix a problem with new saves not being able to remove locations.