Hi Ambimind,

The problem is your curve is not closed.
If you zoom up to the red cicled area in the picture you can see that the ends don't meet, also if you pick a curve or any object in MoI it tells you in the top right hand corner (circled green) what type of curve or object it is, in this case it says 'Curve' which means it's an open curve if it was a closed curve it would say 'Closed crv' if you fix this up so it's a closed curve it will trim as normal and no need for projection.





Cheers