It's a big one! In this update the API was rewritten to fix some long-standing issues that could now finally be resolved with a much cleaner codebase.
As this is a full rewrite, a real changelog is not easily created, which simply means that not all changes will be listed here.
Old Save Files will no longer work with this version.
For a full guide on how to use this new version, see https://docs.crazyadvancements.endercentral.eu

General Changes:
- Added New Command: /setprogress <Player> <Manager> <Advancement> <Progress> including Tab Completion
- Removed the File Advancement Manager which loaded Advancements from JSON files

API Changes:
- Renamed Main Class from CrazyAdvancements to CrazyAdvancementsAPI
- Added New Class ToastNotification for easier creation of Toasts
- Added New Class AdvancementsPacket which allows you to send Advancements Packets yourself
- Changed how Criteria works, Advancements now expect an instance of the Criteria class instead of a Number which also allows for more complex Advancements
- Changed how Progress is stored for an Advancement
- Changed where Save Files are located
- Changed Save File Format
- Removed SaveMethod
- Removed Several Events related to Criteria
- Removed Several Save and Load Methods from AdvancementManager