KYATONIPU'S PROFILE

Hey! First post on here and first time making a game in RPG Maker. I'm using XP, making a game for my senior project, and when I try to do a test battle against troops, when I use the 'Attack' command, I will very often get an error that is as follows:

Script 'Game_BattleAction' line 62: NoMethodError occurred.

undefined metho 'scope' for nil:NilClass

I have no idea how to fix this. My line 62 code in the Game_BattleAction section is as follows:

.include?($data_skills.scope)
return true
end

Can somebody please help me out? Thanks if you do!