Comment 6 for bug 807439

I stitched your project and see the same seam artefacts, I'll attach a scaled down version.

This is an enblend bug, though I have never seen it before. I used dummy images so the problem is caused entirely by the geometry of photos in your project (and not their content). The project looks fine, you have a good overlap, this should work.

A possibility are that enblend has some implicit expectation that panoramas are shot left-to-right, and that your right-to-left shooting style is exposing the bug. Though this seems unlikely.

You can remove all ordering by setting '-a' in the blender options before stitching, you could try this.