Version 2.12 not working

[Chibilena]

Describe the bug
As soon as I join the server, I am immediately kicked with the error.
I don't have any code I ran the plugin on the server.
https://prnt.sc/y0xfvn

NPCLib JAR name
npclib-plugin 2.12-SNAPSHOT

	<dependency>
		<groupId>net.jitse</groupId>
		<artifactId>npclib-plugin</artifactId>
		<version>2.12-SNAPSHOT</version>
		<scope>compile</scope>
	</dependency>

Server version
paper 1.16.5

[JitseB]

Ah yeah, okay. That shouldn't happen. I'll try to look into this on the weekend.