28.07 08:15:46 [Server] WARN "Essentials v2.0.1-b499" has registered a listener for org.bukkit.event.player.PlayerPickupItemEvent on method "public void com.earth2me.essentials.EssentialsPlayerListener.onPlayerPickupItem(org.bukkit.event.player.PlayerPickupItemEvent)", but the event is Deprecated. "Server performance will be affected"; please notify the authors [Zenexer, ementalo, Aelux, Brettflan, KimKandor, snowleo, ceulemans, Xeology, KHobbits, md_5, Iaccidentally, drtshock, vemacs, SupaHam, md678685].

EssentialsX version (/essentials): Essentials reloaded 2.0.1-b499

Server software (/version): version git-Spigot-596221b-2c5c611 (MC: 1.12) (Implementing API version 1.12-R0.1-SNAPSHOT

EssentialsX config (if applicable): N/A

This is due to the latest Spigot 1.12 built (today). Many plugins warned.

I received same error after updating spigot a bit ago. Glad it's nothing to worry about

Yeah I'm aware. Is this going to be fixed within essentials? Or is it something I don't need to worry about?

It will be fixed. It's not something you need to worry about.

Forgot to mention this has been fixed in 210494d. You can grab the fix from build 501 on the CI server.