Seeing a black frame when applying Looks 3 or 2 is typically caused by one of these variables:
- Footage was rendered before bringing it into Looks: If you'd applied Looks after rendering, you'll need to try either removing and re-applying the effect, or clearing out your editing application's cache. In the future, you'll want to try to and apply Looks to your footage before doing any rendering.
- The clip has time remapping: Any sort of slowing down or speeding up on your footage before bringing it into Looks can result in either a black (or even a wrong frame) getting displayed in the Looks builder. Remove your time adjustments, re-apply Looks, and check to see if the right frame gets pulled.