SENPAIAL'S PROFILE

I tried to use this script as well, since I'm not too good with the syntax of Rpg Maker XP yet, but here's the error message that I recieved that I can assume duncanmet also got:

Script 'Difficulty' line 377: NoMethodError occured.

undefined method '' for nil:NilClass

I read through the instructions and some parts were a bit confusing, but it would most likely be that I don't know what I'm doing. Please let me know how I can fix this.