Hugin 360 problems

That looks like you missed covering the entire scene, and enblend is attempting to blend the black (uncovered) area of the scene with the bits it does have. I would suggest checking that you've cropped member images (if you're using a circular fisheye lens), that you've got enough overlap to cover everything (you want about 1/3 of the frames to overlap in every direction), and that you've applied masks correctly.

See also: What are the best techniques to take 360° panoramas?