It says in the script instructions:
# Also place all weapons ID except SP damaging and absorbing ones, into the
# "ALL_WEAPONS_IDS", because if you don't, a nasty bug will prevent you from
# dealing damage with normal attack. Cool, huh ?
The line the error code is pointing to is
self.damage *= elements_correct(attacker.element_set)
The error is saying the variable or method
damage is currently equal to
nil. The class
NilClass has no defined method for the
* operator.
The reason
damage is nil is because you didn't configure the script correctly, as indicated above.
Thank you! I wasn't sure what that weird bug was that was mentioned in the script. I have it working and was able to add a section for dexterity based attacks.