crash in random moment, 2 error

[2pac nakur]

"Script 'UMS new' line 196: NoMethodError occurred.
undefined method 'attr_accessor' for Game_System:Class"

"script `----REAL MAIN-------` line 20: ArgumentError occurred.
undefined class/module RPG::"

this error crash game, i do not nothing something strange just play, windows username english, path to game english, what i can do to fix, if it help, other rmg maker it crash too but it not give error message
sorry for my bad english, I use my little knowledge of English and translator