French Tutorial: https://www.youtube.com/watch?v=rbVPZewRmbY
The old API is deprecated from 1.0.0, please use the new API.
We focused for the 1.0.0 release at making ViaVersion multiplatform compatible. This also meant we had to change the way ViaVersion and the api worked,
The class ViaVersion is deprecated, by usages like ViaVersion.getInstance() use Via.getAPI() intead.