Server Crash: https://mclo.gs/tp9LS7P (Not actually a server)
Client Crash: https://mclo.gs/v47pDT4 (tho, not really important)

Worked fine on v2.0.13+1.18

Stopped working on v2.0.16+1.18.2

This is an issue with Megane and their compact for alloy forgery with the 1.18.2 version. Such needs to be fixed on their side with there accessor mixin.

Ah, okay! Do I need to report that to them or something like that?

Yes

Reported #55 :)

Fixed in the latest release of Megane, thanks for reporting