Error when trying to enable more than 18 boosts (probably related to GUI size)

[stw222]

When i try to add more than 18 active boosts to my boosts.yml, it gives an error when i try to open the gui.

Im guessing this has something to do with the GUI being 18 slots.
A suggestion could be, that we should be able to make the GUI size customizable

Error from console:
https://pastebin.com/9YfepdG6

Boosts.yml (the boosts i was trying to add are commented out so i don't get the error) :
https://pastebin.com/bw39zkZH

config.yml:
https://pastebin.com/BCV068X2

Server info:
paper-98 1.16.1
Waterfall-365 proxy
Ubuntu MATE 18.04.3 LTS with Linux kernel 5.2.11 64 bit

[milkwalk]

@stw222 yea its related to that :(

i had in mind to completely rework guis system, but i dont work on the plugin as much lately. I will look at the error as this should not happen anyways.