Problem when enabling ShopChest

[CuzImLqve]

Hello,
When I start the server it gives me this error here:

I'm running a 1.8.8 server with ViaVersion to be able to join from that version to 1.18.1, with Java 8 of course. I've installed on the server the latest snapshot on Jenkins that should be able to run on 1.8
I would really appreciate if someone could help me, thanks.