I was recently doing a test video with Trapcode Form. It was fairly simple, the particles behave in a few different ways with a camera getting closer and moving along the particles. However, whenever I try to keyframe the camera movements (either directly using the camera, or parenting it to a Null), I run into a few issues that I can't get rid of. For one, as soon as I activate a keyframe for one aspect of the camera or Null, when I change that aspect, the Preview image doesn't update. The camera will remain as it was, though occasionally it will update when I try to RAM-Preview. If it does work, and I try anything more than just two keyframes, the keyframes don't behave correctly at all. They get the infamous wobble and the camera changes sporadically where there aren't any keyframes. This only applies to Cameras and layers that I parent Cameras to. I don't have the same issue with other 3d layers. I have tried changing the keyframe spatial interpolation to Linear on all the keyframes, but they are either already linear, or it doesn't fix the problem. In my preferences, I even set my default spatial interpolation to Linear, yet still to no avail. I have restarted the project from scratch and still have the same problem every time. I posted this on CreativeCOW and one guy offered to open/render my file to see if it worked on his PC. He said he didn't have any issues, and that it rendered just fine. Any ideas of what the issue could be? I've been searching everywhere and can't seem to find anyone with a similar problem.
If you are willing to post your project for someone to look at, do so here. Make sure to post the simplest possible project that exhibits the issue, to make the troubleshooting process easier.
First, turn off disk cache. Second, purge everything. Third, restart AE. If that doesn't fix it reboot.
This almost certainly is a cached frames problem and not in some weirdness with the camera movement. If you look at the camera in another view you'll see that the camera is moving properly along it's path.