Object split using loft

Loft doesn’t split an object. Error given “Split failed, objects may not intersect or intersections may not split object”. Not sure what’s causing this or how to fix. Can anyone advise? File attached.

Basically, trying to bevel ends of a sloping tube at 45 deg. If there is a better way please suggest. Thanks.

Tolerance check.3dm (158.0 KB)


I used your surface and curve to trim away the surfaces.
Can you sketch the surface / geometry you re trying to get here ?