Video filter missing -- and can't export anything

Hi,

1. I made a simple AE project -- one image is morphed into another using Time Warp.
2. Everything looks correctly
3. When I export as Premiere project and then open that project, I get a 'Video filter missing' error, and instead of the morphed project there are just separate image files. (I'm following the same procedure as in earlier cases where the export did work.)
4. When I instead export as video, in any format, the resulting videos are blank -- though I can see in Encoder that the actual video seems to be processed frame by frame.

AE, Encoder and Premiere are latest updates from today.

Any ideas as to what might be wrong?

EDIT: I tried exporting again, as AVI and Quicktime: In both cases, the results are now empty and rendered in a second; as opposed to earlier today where it took a couple of minutes to render, and the results were actual videos of the expected length (though they were just blank/white).

EDIT 2: I've tried rendering using both GPU Accelleration (Cuda) and software only; same results.