Release notes for Plex Version 1.25.1.5286 upgrade libraries

You can always find the latest release notes in this announcement thread. If you “bookmark” the thread (using the forum “bookmark” button… not the browser feature), you can get a notification if there’s a new release (incl. its details).

Upgrading your libraries isn’t specifically linked to the recent server update. This will update existing libraries to use the current generation Plex agents (namely: Plex Movie, Plex TV Series and Plex Music). Existing metadata and customizations shouldn’t be modified by that.
If you’re relying on 3rd party / complementary agents you might not want to upgrade as the new agents no longer support those complementary agents (e.g. opensubtitles.org w/ automatic subtitle download).