Digital Light & Color

I have opened a file, performed some transformations, then created a new file of the same dimensions and added a gradient to it, then in the original branch, used the gradient in a filter transformation, did some more transformations and then performed a Save Back, saving the script with image copies.
When I try to reopen the saved script (having left my original branch and the new file branch open), partway down the main branch, at the filter transformation which uses the new file with the gradient, the transformation reports "Error: Filter image size mismatch". Subsequent transformations of course report "Bad input image".

The main branch opened with an image size of 9521 x 3311. The next transformation was a Warp, and the resulting image was 9520 x 3311. The new file from which I made the gradient was also 9520 x 3311.

What can I provide that could help in diagnosing the problem?

I think I see the problem and how to circumvent it. The original file was 9521 x 3311, and my first operation on it was a warp which left an image size of 9520 x 3311, and the new file I created for the filter transformation that follows the warp was also 9520 x 3311. However, when PWP opened and ran my saved script, the output of the warp transformation was 9521 x 3311, not 9520. Naturally then, in the filter transformation, there would be a size mismatch between the image and filter. Therefore, I edited the saved script to change the new file size to 9521, and the script successfully ran and produced the correct output image

Conclusion:
The output size of images from the warp transformation are not perfectly reproducible.

I believe this is a problem that I fixed in 8.0.74.

Yes, .74 appears to fix it. Amazingly fortuitous timing.