Grimrock

Hello there, I'm trying to make a combination puzzle with plates but having trouble can someone help.
plates set on toggle, error- attemp to call method 'isActivated' (nil value)?

function plateLevers()
if combination_plate_1a.occluder:isActivated() and not
combination_plate_2a.occluder:isActivated() and not
combination_plate_3a.occluder:isActivated() and not
combination_plate_4a.occluder:isActivated() and
combination_plate_5a.occluder:isActivated() and not
combination_plate_6a.occluder:isActivated() and not
combination_plate_7a.occluder:isActivated() and not
combination_plate_4a.occluder:isActivated() and
combination_plate_9a.occluder:isActivated() then

combination_plate_door_1.door:open()
else
combination_plate_door_1:close()
end
end

pattern is facing north
x o o
o x o
o o x

It's not "occluder", it's "floortrigger"...

thanks

Works now

perfect