Here's the typical reasons why Looks would pull a black or incorrect frame into the Looks Builder:
- Time remapping done prior to applying Looks: You'll want to remap (slow down/speed up) footage after applying Looks, not prior, otherwise the wrong frame often gets pulled into the Looks builder
- (Premiere/After Effects) Applying to an Adjustment Layer: This isn't fully supported just yet; Looks should be applied directly to the clip it's trying to work with, not to an Adjustment Layer.
- (FCP X only) Looks is not at the top of the tool chain: Make sure Looks is the first/top-most applied effect prior to opening it in the Looks builder.
- Footage was rendered prior to applying Looks: Render footage after Looks is applied, not before. If you've already rendered it, clean out the render cache and try applying Looks once more.
- The plugin/host need to be udpated: Check that both Looks and the host are up-to-date, as sometimes one or both can affect how frame data gets pulled into the builder.