Split failed, objects may not intersect or intersections may not split object. what to do

Someone Please Help me! I am new in rhino and i am not able to split this ellipse into half.

What commands are you using? What is the splitting object?

Intersect the object to be split and the splitting object, and then check that the resulting curve is either closed or ends at open edges of the object to be split.

“New to Rhino” - have you worked through any tutorials?

Thank you for reply!
i tried a lot with split commands and Boolean split but nothing changed.

i am trying to split elliptical solid in half to create a architectural form for my design. i attach a screenshot to better explain my problem .

yah. i have seen lot of tutorials but nothing work.

Love this part:

Download the current 90 day eval and then, if you like Rhino after 90 days, buy an edu license for the duration of your studies…

Missed that. If I’d seen it I would not have replied.