Then the problem is that the BVH file has MORE bones than the model. Poser reads the data and can't find a bone to apply the data to.
Usually P4 models (Posette and Dork) have enough bones to accept everything from a BVH file. I have applied quite a few BVH files (there's literally hundreds of thousands of them free on the Web, and I do mean officially legitimally free!) to Posette, Judy, V3/M3. 
Almost always they require cleanup, especially at feet and toes, often at the hands and arms too.I often write dedicated Python scripts for the cleanup, I don't want to clean up 1200 frames by hand....

The pen is mightier than the sword. But if you literally want to have some impact, use a typewriter

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