Why is 'split' pipe creating this odd split?

The blue curve was piped but when I went to split curve and pipe (hid pipe in image) it came out with this glitchy split. Any ideas of why this may have happened?

Hi Petra, one idea is that the pipe you created is slightly selfintersecting, that its just a little too wide for its curvature. another idea is that you absolute tolerance is too low, so try adding a 0 to something like 0.01 or 0.001 and try the split command again. if that does not work maybe post the file if its possible for you.

Thank you, it turned out the pipe was self intersecting, just dropped down the diameter .2 mm and it worked.