Type of bug

Error in console, Other unexpected behaviour

/ess dump all output

https://essentialsx.net/dump.html?id=1446c391fdf64b74a25ad691bb0dfc47

Error log (if applicable)

https://paste.gg/p/anonymous/5a6d0990233747839125d60decba2c60

Bug description

When running "/createkit " it says "Error: 4" in chat and doesn't actually create the kit. Also gives console error I attached.

Steps to reproduce

1. Create a brand new 1.8.8 Spigot server
2. Add the EssentialsX plugin
3. /op yourself
4. Get items in your inventory
5. Run /createkit

Expected behaviour

Creates a kit from the items in your inventory.

Actual behaviour

Says "Error: 4" in chat and doesn't create the kit. Also gives console error I attached.