[CRITICAL] General issues with new Minecraft versions

[MeowIce]

Debug info

Plugin Version: v1.2.11 (both on SpigotMC and Github are affected).
Minecraft Version: Purpur 1.20.2/1.20.4 (Build #2143 and up).

Symptoms:

On 1.20.2

Press L to load up the Advancements GUI, and hover the mouse on the "Advancement Tree" icon, the texts are overlapped. Something looks like #184

On 1.20.4+

When a player joins the server, the console says:
[CustomAdvancements] Could not send advancements to [player]
Opening the Advancements UI:
As you see, only Minecraft's default advancements are loaded, although my config already had been customized. Same as #179

Expectations:

On 1.20.2, the texts no longer overlap.
On 1.20.4, the plugin properly loads and handles data.

[YuuYN]

good features to dupe