Is there any reason why you have to make another timer class that does the exact same thing? Why can't you use the default one? In order to make a second one, you will need to add more variables to some of the pre-existing scripts to get this to work. What you have right now wouldn't even function properly, if at all.
NoMethodError means exactly what it says: the method you are trying to use has not been defined anywhere within your scripts. You can't just slap on a '2' at the end of timer_working and expect it to do something. Computers are fast, not smart.
You will need to make an attr_accessor in Game_System called timer_working2 first.
class Game_System
attr_accessor: timer_working2
alias init_2nd_timer initialize
def initialize
@timer_working2 = false
init_2nd_timer
end
end
But after doing that, you will need to create the Sprite_Timer instance in Spriteset_Map, etc. In other words, too much trouble for its worth.