Can be reverted to via Steam Beta branch.

Released alongside CKII Subscription Service.

This is more applicable for mods, who have various levels of compatibility with new patches.

You cannot activate Conclave if you're playing 2.4.X and older, and you cannot activate Conclave and Horse Lords if you're playing 2.3.X and older.

Note that newer DLCs cannot be activated if you're playing on an older patch version.Hotfixes are commonly released shortly after major patches to fix any unforeseen bugs that came with the previous update, or independently to fix newly-discovered bugs or exploits. Hotfixes are very small updates to the game that usually fix only a few bugs and may contain a few changes to the gameplay as well.They are sometimes released alongside a new, major DLC when this occurs a portion of the DLC's features are usually shipped as part of the coinciding free patch, thus made available to anyone who has the base game. Patches fix many bugs and/or implement balance tweaks.Patches and hotfixes are free updates for Crusader Kings II, though there they are different in purpose:

Crusader kings 263 patch download