Hi Chris,
Bit of head scratching. On the project I am working on, the null layer is never available to be assigned to the Track Motion. So I tried using one of the Tutorial project movie clips and it worked. So something challenging on my project. In trying to work out what might be happening, I am doing track motion on a small section of a clip only. Would I be better to separate out the bits I want to track motion, do the processing, and then reintegrate them back into the whole project?
In addition, when I followed your instructions on the tutorial project clip, the solid moved with the background, where I am hoping to have the solid fixed with the track point centred on the solid. Or was I doing something wrong?
Regards
Andrew