Why won't the alarm light in this file render?

I’m trying to create a simple animation (robot simple animation flashing light.blend (1.22 MB)). When the robot moves in front of the mirror, I want a red light to flash on and off.

When I first created the light, it rendered correctly. But after adding in keyframes to make it flash on and off, now the light doesn’t render at all. Can anyone tell me why not?

Thanks

Some some reason you have changed the Duplication setting from None to Faces


Great, thank you.