It's hard for me to figure out what's going on here because that first script is in Japanese and I don't have VX installed anymore.
I'm also having a difficult time understanding what you're trying to do with the script... Are you using these scripts only for players, or for enemies too?
At first glance, it looks like the error is with the "Multiple Attacks" script trying to read the variable "weapons" for enemies. Enemies do not have weapons, so the variable doesn't exist for them.