Headlights won't lock in place

[Alex Walker]

I bought a new mounting plate for the driver's side head light and installed it but now when I slide the head light in place, it doesn't lock. The removal tool rotates and you can hear that loud pop but you can still pull the head light out by hand. I had taken out the right side head light as well to make sure I had the mounting plate in properly and it too won't lock in place now. The removal tool rotates almost freely with only a slight popping sound.

Any tips?