Is not a valid member of KeyframeSequenceProvider?!

i was sorta doing simple scripting since i am a starter student, i tried making blinking light using instance.new to test it, so i made this script and put inside the part i want it in:

while true do
    light = game.Instance("PointLight", script.Parent)
    light.Range = 15
    wait(2)
    light:Destroy()
    wait(3)
end

it does not work , i tried deleting light:destroy() but it still didn't work, and i was confused until i opened my output , there i was even buffled because it said: "PointLight is not a valid member of KeyframeSequenceProvider" i did some research and correct me if i'm wrong but... this error only happens when editing the animation editor or something...

there's nothing in the world btw , theres only 1 Baseplate and a part that i'm editing which is empty only having this script.

now i'm stunned with confusing questions...